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Molecular mechanisms of mutagenesis and resistence in CML cell lineages
Karasová, Dominika ; Čuřík, Nikola (advisor) ; Savvulidi Vargová, Karina (referee)
Chronic myeloid leukemia is a clonal haematopoietic disease, with characteristic BCR-ABL1 fusion gene. Despite the significant improvement in patient treated with tyrosine kinase inhibitors (TKI), 20-30 % of patients develop resistance. One of the main causes of treatment failure are mutations in the BCR-ABL1 kinase domain (KD). The aim of this work was to elucidate the molecular mechanisms of resistance and mutagenesis development in CML using an in vitro CML model KCL-22. The main part of this work was focused on the identification of genes involved in DNA damage response and repair, that could play a role in the process of mutagenesis of BCR-ABL1. We used the RT2 Profiler PCR Arrays method for the group of selected genes regulating DNA damage response and repair. We identified the genes XRCC6 and PARP1 whose gene expression was significantly and specifically decreased during KD BCR-ABL1 mutagenesis. Products of these genes are involved in repairing DNA double-strand breaks through non-homologous end joining (NHEJ). During study of the KD BCR-ABL1 mutagenesis we also found that clones, which developed mutations, did not show the increased BCR-ABL1 expression in the beginning of the culture compared to the clones in which mutations have not evolved. Key words: myeloid leukemia, mutation,...
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Expression of WT1 and its splicing variants in myeloid leukemias
Macháčková Lopotová, Tereza
3 Abstract Myeloid leukemias include malignant diseases characterized by clonal expansion of the myeloid cell lineage. While in case of chronic myeloid leukemia (CML), the main cause of the disease has already been identified - t(9;22) and the aktivity of the fusion product of the translocation BCR-ABL, acute myeloid leukemia (AML) has been associated with plenty of different translocations and mutations. The aim of this work was to contribute to the improvement of monitoring of patients with myeloid leukemias via detailed study of the panleukemic marker Wilms tumor gene 1 (wt1) expression. Prognostic value of wt1 expression has been proved for AML patients, however, it has not yet been confirmed for CML patients. Expression of different wt1 variants (more then 36 protein products) is known very poorly in both, AML and CML as well as in normal hematopoiesis. Most of the study is focused on CML, only limited parts are dedicated to AML. In the first part of the work, we clearly proved prognostic value of total wt1 mRNA expression for CML patients. Statistical evaluations revealed critical wt1 values which enable to specify prognosis of patients responding non-optimally to imatinib. Bcr-abl looses much of its prognostic value in these patients. Further, we have designed and optimized PCRs for selected wt1...
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Molecular mechanisms of mutagenesis and resistence in CML cell lineages
Karasová, Dominika ; Čuřík, Nikola (advisor) ; Savvulidi Vargová, Karina (referee)
Chronic myeloid leukemia is a clonal haematopoietic disease, with characteristic BCR-ABL1 fusion gene. Despite the significant improvement in patient treated with tyrosine kinase inhibitors (TKI), 20-30 % of patients develop resistance. One of the main causes of treatment failure are mutations in the BCR-ABL1 kinase domain (KD). The aim of this work was to elucidate the molecular mechanisms of resistance and mutagenesis development in CML using an in vitro CML model KCL-22. The main part of this work was focused on the identification of genes involved in DNA damage response and repair, that could play a role in the process of mutagenesis of BCR-ABL1. We used the RT2 Profiler PCR Arrays method for the group of selected genes regulating DNA damage response and repair. We identified the genes XRCC6 and PARP1 whose gene expression was significantly and specifically decreased during KD BCR-ABL1 mutagenesis. Products of these genes are involved in repairing DNA double-strand breaks through non-homologous end joining (NHEJ). During study of the KD BCR-ABL1 mutagenesis we also found that clones, which developed mutations, did not show the increased BCR-ABL1 expression in the beginning of the culture compared to the clones in which mutations have not evolved. Key words: myeloid leukemia, mutation,...
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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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Expression of WT1 and its splicing variants in myeloid leukemias
Macháčková Lopotová, Tereza
3 Abstract Myeloid leukemias include malignant diseases characterized by clonal expansion of the myeloid cell lineage. While in case of chronic myeloid leukemia (CML), the main cause of the disease has already been identified - t(9;22) and the aktivity of the fusion product of the translocation BCR-ABL, acute myeloid leukemia (AML) has been associated with plenty of different translocations and mutations. The aim of this work was to contribute to the improvement of monitoring of patients with myeloid leukemias via detailed study of the panleukemic marker Wilms tumor gene 1 (wt1) expression. Prognostic value of wt1 expression has been proved for AML patients, however, it has not yet been confirmed for CML patients. Expression of different wt1 variants (more then 36 protein products) is known very poorly in both, AML and CML as well as in normal hematopoiesis. Most of the study is focused on CML, only limited parts are dedicated to AML. In the first part of the work, we clearly proved prognostic value of total wt1 mRNA expression for CML patients. Statistical evaluations revealed critical wt1 values which enable to specify prognosis of patients responding non-optimally to imatinib. Bcr-abl looses much of its prognostic value in these patients. Further, we have designed and optimized PCRs for selected wt1...
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Expression of WT1 and its splicing variants in myeloid leukemias
Lopotová, Tereza ; Moravcová, Jana (advisor) ; Zemanová, Zuzana (referee) ; Rázga, Filip (referee)
Myeloid leukemias include malignant diseases characterized by clonal expansion of the myeloid cell lineage. While in case of chronic myeloid leukemia (CML), the main cause of the disease has already been identified - t(9;22) and the aktivity of the fusion product of the translocation BCR-ABL, acute myeloid leukemia (AML) has been associated with plenty of different translocations and mutations. The aim of this work was to contribute to the improvement of monitoring of patients with myeloid leukemias via detailed study of the panleukemic marker Wilms tumor gene 1 (wt1) expression. Prognostic value of wt1 expression has been proved for AML patients, however, it has not yet been confirmed for CML patients. Expression of different wt1 variants (more then 36 protein products) is known very poorly in both, AML and CML as well as in normal hematopoiesis. Most of the study is focused on CML, only limited parts are dedicated to AML. In the first part of the work, we clearly proved prognostic value of total wt1 mRNA expression for CML patients. Statistical evaluations revealed critical wt1 values which enable to specify prognosis of patients responding non-optimally to imatinib. Bcr-abl looses much of its prognostic value in these patients. Further, we have designed and optimized PCRs for selected wt1...
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