|
|
Molecular requirements of LACTB-induced tumor suppression
Jakoubě, Pavel ; Kečkéšová, Zuzana (advisor) ; Rohlenová, Kateřina (referee)
LACTB is a recently discovered mitochondrial tumour suppressor protein operating in many different types of tissues. Its mechanism-of-action seems to be context dependent as it has been shown to suppress carcinogenesis through the induction of cell cycle arrest, apoptosis, differentiation and suppression of EMT. These processes can be further dependent on alterations of lipid metabolism and interactions with additional tumour suppressors and signalling pathways. LACTB is derived from bacterial penicillin binding proteins, is localized to the mitochondrial intermembrane space and possesses enzymatic activity. It was shown to form filaments, which consist of two intertwined antiparallel chains, suggesting its role in the organisation of mitochondrial intermembrane space. In the first aim of my thesis, I wanted to examine in more detail the molecular requirement for LACTB's filament formation with the specific focus on the role of disulphide bonds in this process. In the second aim of my thesis, I intended to uncover the binding partners of LACTB, which might have a role in the filament formation. Realizing both aims will uncover important requirements for the proper folding and biological activity of LACTB. Key words: LACTB, tumour suppressor, cancer, structure, disulphide bonds, protein interactions
|
|
|
Importance of glycolysis and oxidative phosphorylation in the metabolism of mesenchymal stem cells
Fráňová, Markéta ; Krulová, Magdaléna (advisor) ; Rohlenová, Kateřina (referee)
Mesenchymal stem cells (MSCs) are classified as multipotent stem cells. They possess the ability to differentiate into many cell types, promote angiogenesis, increase cell survival in damaged tissue and modulate the immune response. These functions of MSCs are used in the treatment of various injuries and some diseases. This work characterizes MSCs, with a focus on their energy metabolism, specifically on the switch in their metabolic phenotype between glycolysis and oxidative phosphorylation in different states of MSCs, during cell culture and after transplantation. Finally, two modulations of MSC metabolism are presented, including cultivation in a hypoxic environment and quiescence induced by serum deprivation, which increase cell survival under the ischemic conditions that MSCs enter after transplantation. Key words: mesenchymal stem cells, metabolism, glycolysis, oxidative phosphorylation
|
|
|
Targeting mitochondria to overcome resistance of breast cancer to therapy
Rohlenová, Kateřina ; Neužil, Jiří (advisor) ; Špíšek, Radek (referee) ; Vítek, Libor (referee)
(EN) Tumours are heterogeneous and consist of multiple populations of cells. The population of cells with tumour-initiating capability is known as cancer stem cells (CSC). Cells with increased stemness properties and elevated resistance to anti-cancer treatment have been shown to be highly affected upon decline of mitochondrial respiration, linking the concept of CSCs to deregulated bioenergetics. Consistently, functional electron transport chain (ETC) is crucial in tumorigenesis. Expression of HER2 oncogene, associated with resistance to treatment in breast cancer, has been connected with regulation of mitochondrial function. We therefore investigated the possibility that manipulation of mitochondrial bioenergetics via disruption of ETC eliminates the conventional therapy-resistant populations of tumour, such as CSCs and HER2high cells. We demonstrate that HER2high cells and tumours have increased complex I-driven respiration and increased assembly of respiratory supercomplexes (SC). These cells are highly sensitive to MitoTam, a novel mitochondria-targeted derivative of tamoxifen, acting as a CI inhibitor and SC disruptor. MitoTam was able to overcome resistance to tamoxifen, and to reduce the metastatic potential of HER2high cells. Higher sensitivity of HER2high cells to MitoTam is dependent on...
|
|
|
Targeting mitochondria to overcome resistance of breast cancer to therapy
Rohlenová, Kateřina ; Neužil, Jiří (advisor) ; Špíšek, Radek (referee) ; Vítek, Libor (referee)
(EN) Tumours are heterogeneous and consist of multiple populations of cells. The population of cells with tumour-initiating capability is known as cancer stem cells (CSC). Cells with increased stemness properties and elevated resistance to anti-cancer treatment have been shown to be highly affected upon decline of mitochondrial respiration, linking the concept of CSCs to deregulated bioenergetics. Consistently, functional electron transport chain (ETC) is crucial in tumorigenesis. Expression of HER2 oncogene, associated with resistance to treatment in breast cancer, has been connected with regulation of mitochondrial function. We therefore investigated the possibility that manipulation of mitochondrial bioenergetics via disruption of ETC eliminates the conventional therapy-resistant populations of tumour, such as CSCs and HER2high cells. We demonstrate that HER2high cells and tumours have increased complex I-driven respiration and increased assembly of respiratory supercomplexes (SC). These cells are highly sensitive to MitoTam, a novel mitochondria-targeted derivative of tamoxifen, acting as a CI inhibitor and SC disruptor. MitoTam was able to overcome resistance to tamoxifen, and to reduce the metastatic potential of HER2high cells. Higher sensitivity of HER2high cells to MitoTam is dependent on...
|
guest ::
