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Adhesion structures of leukemia cells and their regulation by Src family kinases
Obr, Adam
Adhesion signaling is a field of cell biology studied mostly on adherent cell types. However, hematopoietic cells grow in suspension, and use adhesion to the extracellular matrix (ECM) only in their early development, or - in case of differentiated cells - to perform the tasks they are specialized for. Peripheral leukemic cells are derived from more or less immature hematopoietic precursors that have, among other alterations, defects in adhesion to the bone marrow microenvironment. On the other hand, leukemic stem cells (LSC) use adhesion to the bone marrow ECM as a mean to evade chemotherapy, and are a source of the minimal residual disease, and of the disease relapses. Kinases of the Src family (SFK) are known regulators of adhesion signaling in adherent cell types, and their overexpression and/or hyperactivation is often seen in malignant diseases. They are also involved in hematooncologic disease progression and resistance to therapy, particularly in several types of leukemias. In the present work, we used a variety of methods including microimpedance measurement, fluorimetric measurement of adhered cell fraction, immunoblotting, confocal microscopy, and interference reflection microscopy. Our results indicate that active Lyn kinase, a hematopoietic SFK, is present in adhesion structures of...
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Adhesion structures of leukemia cells and their regulation by Src family kinases
Obr, Adam ; Kuželová, Kateřina (advisor) ; Brdička, Tomáš (referee) ; Brábek, Jan (referee)
Adhesion signaling is a field of cell biology studied mostly on adherent cell types. However, hematopoietic cells grow in suspension, and use adhesion to the extracellular matrix (ECM) only in their early development, or - in case of differentiated cells - to perform the tasks they are specialized for. Peripheral leukemic cells are derived from more or less immature hematopoietic precursors that have, among other alterations, defects in adhesion to the bone marrow microenvironment. On the other hand, leukemic stem cells (LSC) use adhesion to the bone marrow ECM as a mean to evade chemotherapy, and are a source of the minimal residual disease, and of the disease relapses. Kinases of the Src family (SFK) are known regulators of adhesion signaling in adherent cell types, and their overexpression and/or hyperactivation is often seen in malignant diseases. They are also involved in hematooncologic disease progression and resistance to therapy, particularly in several types of leukemias. In the present work, we used a variety of methods including microimpedance measurement, fluorimetric measurement of adhered cell fraction, immunoblotting, confocal microscopy, and interference reflection microscopy. Our results indicate that active Lyn kinase, a hematopoietic SFK, is present in adhesion structures of...
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Crosstalk of integrin and mTOR signaling
Teglová, Lucie ; Rösel, Daniel (advisor) ; Libus, Jiří (referee)
iv Abstract Crosstalk of integrin and mTOR signalling is an essential process that monitors cellular interaction with extracellular matrix and transmits these inputs to cell growth signalling. Although adhesion status of the cell monitored by integrin signalling is clearly important for regulation of cellular growth, a little is known about the crosstalk of integrin and mTOR signalling. In this study, we employed two different approaches to describe and elucidate character of this crosstalk. p130Cas is an adaptor protein phosphorylated by Src kinase and focal adhesion kinase upon integrin ligand binding and implicated in cell adhesion, motility and survival in both Src-transformed and untransformed cells. Recently, p130Cas was also described in cellular pathology, mainly by its ability to stimulate cell invasion and metastasis. In this study, we described that p130Cas affects mTOR signalling in Src-transformed cells. Substrate domain of p130Cas was found to be indispensable for this effect and is also responsible for serum-induced activation of mTOR signalling. In addition, we prepared cell lines overexpressing various Rheb protein versions and characterized them in context of mTOR signalling, integrin signalling and cell cycle progression. Interestingly, a cell line overexpressing constitutively active...
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Adhesion structures of leukemia cells and their regulation by Src family kinases
Obr, Adam ; Kuželová, Kateřina (advisor) ; Brdička, Tomáš (referee) ; Brábek, Jan (referee)
Adhesion signaling is a field of cell biology studied mostly on adherent cell types. However, hematopoietic cells grow in suspension, and use adhesion to the extracellular matrix (ECM) only in their early development, or - in case of differentiated cells - to perform the tasks they are specialized for. Peripheral leukemic cells are derived from more or less immature hematopoietic precursors that have, among other alterations, defects in adhesion to the bone marrow microenvironment. On the other hand, leukemic stem cells (LSC) use adhesion to the bone marrow ECM as a mean to evade chemotherapy, and are a source of the minimal residual disease, and of the disease relapses. Kinases of the Src family (SFK) are known regulators of adhesion signaling in adherent cell types, and their overexpression and/or hyperactivation is often seen in malignant diseases. They are also involved in hematooncologic disease progression and resistance to therapy, particularly in several types of leukemias. In the present work, we used a variety of methods including microimpedance measurement, fluorimetric measurement of adhered cell fraction, immunoblotting, confocal microscopy, and interference reflection microscopy. Our results indicate that active Lyn kinase, a hematopoietic SFK, is present in adhesion structures of...
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Crosstalk of integrin and mTOR signaling
Teglová, Lucie ; Libus, Jiří (referee) ; Rösel, Daniel (advisor)
iv Abstract Crosstalk of integrin and mTOR signalling is an essential process that monitors cellular interaction with extracellular matrix and transmits these inputs to cell growth signalling. Although adhesion status of the cell monitored by integrin signalling is clearly important for regulation of cellular growth, a little is known about the crosstalk of integrin and mTOR signalling. In this study, we employed two different approaches to describe and elucidate character of this crosstalk. p130Cas is an adaptor protein phosphorylated by Src kinase and focal adhesion kinase upon integrin ligand binding and implicated in cell adhesion, motility and survival in both Src-transformed and untransformed cells. Recently, p130Cas was also described in cellular pathology, mainly by its ability to stimulate cell invasion and metastasis. In this study, we described that p130Cas affects mTOR signalling in Src-transformed cells. Substrate domain of p130Cas was found to be indispensable for this effect and is also responsible for serum-induced activation of mTOR signalling. In addition, we prepared cell lines overexpressing various Rheb protein versions and characterized them in context of mTOR signalling, integrin signalling and cell cycle progression. Interestingly, a cell line overexpressing constitutively active...
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