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The role of HOXA9 gene in leukemogenesis
Rejlová, Kateřina ; Starková, Júlia (advisor) ; Fraiberk, Martin (referee)
The evolutionarily conserved family of homeobox genes plays an important role in the development of the anterior-posterior body axis of vertebrates. These genes significantly affect hematopoiesis, the development of blood cells. Extensive studies on homeobox genes in normal hematopoiesis confirmed their role also in leukemogenesis. Since the neoplastic transformation of blood cells, i.e. leukemia, is the most frequent malignancy in children, it has become a major subject of research for many scientists. Precisely in what stage of the malignant transformation the homeobox genes take part has not been shown yet. Neither is it known whether HOX genes are crucial in pathogenesis or whether their deregulation is only a side effect of leukemogenesis. The most studied homeobox gene in leukemogenesis is the HOXA9 gene, which showed correlation with the prognosis of patients with certain leukemias. Many studies describe the effect of HOXA9 in leukemic cell transformation, suggesting this gene could be a promising future target in leukemia therapy. This work is focused on the HOXA9 gene and its association with leukemic transformation of blood cells.
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The SHOX gene and clinical consequences of its defects
Klugerová, Michaela ; Šolc, Roman (advisor) ; Brynychová, Iva (referee)
The SHOX gene ("Short Stature Homeobox-containing Gene") was identified during research of genotype-phenotype corelations in patiens with Turner Syndrome. Absence one alele of this gene was the cause of short stature in these girls. Shortly after, mutations in SHOX gene were identified in patients with Léri-Weill and Langer syndrom, thus in patients with growth failure and skeletal deformities. It is estimated that mutations in SHOX gene or mutations in SHOX regulatory regions affect one in thousand of new born children. Mutations in this gene are one of the most common genetic causation leading to growth failure phenotype. However, the exact role of SHOX gene in bone growth and development is still unknown, therefore it is importnant to study problems with SHOX gene and try to discover mechanism of SHOX protein activity on molecular levels.
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Study of dysregulation of DLX1 protein in myeloid leukemia cells in in vitro and in vivo models
Jelínková, Alena ; Starková, Júlia (advisor) ; Čuřík, Nikola (referee)
The heterogeneous nature of acute myeloid leukemia (AML) worsens the results of patients treated with standard therapy. Understanding the processes of leukemogenesis can contribute to identification of more appropriate treatment. Family of DLX genes (Distal-less homeobox), belonging to the homeobox genes, are associated with haematological malignancies and solid tumors. In the analysis of expression data, the low level of the DLX1 gene was associated with a worse prognosis of patients with AML. In this work we studied phenotypic changes of cell lines with different expression of the DLX1 gene. We silenced the DLX1 gene in AML cell line (sh cells) and compared it to the parental line with higher expression of DLX1 (NSC cells). By cell cycle analysis and apoptosis assays in vitro and in vivo, we have observed the arrest of sh cells in the G0 phase and a lower number of apoptotic cells. Differences were found when measuring the absolute number of cells in time. In in vitro conditions there were less sh cells, in in vivo environment there was significantly higher number of sh cells engrafted in comparison to NSC cells. Further results have shown that sh cells have lower levels of pro-apoptotic proteins and exhibit a higher level of TGF-β targeting PAI-1 gene that activates replicative senescence. We...
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The SHOX gene and clinical consequences of its defects
Klugerová, Michaela ; Šolc, Roman (advisor) ; Brynychová, Iva (referee)
The SHOX gene ("Short Stature Homeobox-containing Gene") was identified during research of genotype-phenotype corelations in patiens with Turner Syndrome. Absence one alele of this gene was the cause of short stature in these girls. Shortly after, mutations in SHOX gene were identified in patients with Léri-Weill and Langer syndrom, thus in patients with growth failure and skeletal deformities. It is estimated that mutations in SHOX gene or mutations in SHOX regulatory regions affect one in thousand of new born children. Mutations in this gene are one of the most common genetic causation leading to growth failure phenotype. However, the exact role of SHOX gene in bone growth and development is still unknown, therefore it is importnant to study problems with SHOX gene and try to discover mechanism of SHOX protein activity on molecular levels.
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Regulation of DLX1 gene expression through AP-1 binding site
Rejlová, Kateřina ; Starková, Júlia (advisor) ; Machová Poláková, Kateřina (referee)
Regulation of expression DLX1 gene, whose elevated levels are detected in patients with acute myeloid leukemia with FLT3-ITD mutations, is not still completely explored topic. The first aim of this study was to determine which selected signaling pathways regulate gene expression of DLX1. ERK a JNK pathways were selected by using qRT-PCR and western blot. These pathways cause activation of the transcription factor AP-1 subunits, the AP-1 putative promoter binding site was identified also in the promoter of the DLX1 gene. The second aim of this study was to test the hypothesis on the regulation of gene expression of DLX1 (via ERK/JNK pathway) through AP-1 binding site on the promoter. Dual luciferase assay using luminescent luciferase activity was performed to test this hypothesis. Gene of the luciferase is contained in the used luciferase vector. The short and the long part of the DLX1 promoter (around AP-1 site) were inserted before the gene of the luciferase in the constructs used in this method. The results of this study indicate that the regulation of gene expression through AP-1 promoter binding site is important but not sufficient part of the regulatory cascade running through ERK and JNK pathway. There must be another transcription factors activated by ERK1/2 kinase which are probably also involved in...
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The role of HOXA9 gene in leukemogenesis
Rejlová, Kateřina ; Starková, Júlia (advisor) ; Fraiberk, Martin (referee)
The evolutionarily conserved family of homeobox genes plays an important role in the development of the anterior-posterior body axis of vertebrates. These genes significantly affect hematopoiesis, the development of blood cells. Extensive studies on homeobox genes in normal hematopoiesis confirmed their role also in leukemogenesis. Since the neoplastic transformation of blood cells, i.e. leukemia, is the most frequent malignancy in children, it has become a major subject of research for many scientists. Precisely in what stage of the malignant transformation the homeobox genes take part has not been shown yet. Neither is it known whether HOX genes are crucial in pathogenesis or whether their deregulation is only a side effect of leukemogenesis. The most studied homeobox gene in leukemogenesis is the HOXA9 gene, which showed correlation with the prognosis of patients with certain leukemias. Many studies describe the effect of HOXA9 in leukemic cell transformation, suggesting this gene could be a promising future target in leukemia therapy. This work is focused on the HOXA9 gene and its association with leukemic transformation of blood cells.
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