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Lineage plasticity of leukemic blasts. Importance for detection of minimal residual disease and study of hematopoesis
Vakrmanová, Barbora ; Mejstříková, Ester (advisor) ; Šálek, Cyril (referee) ; Klener, Pavel (referee)
Acute leukemia is the most common malignancy in children. According to the origin of the leukemic blasts, two types of leukemia are distinguished - lymphoid (ALL) and myeloid (AML). The focus of this thesis is lineage plasticity of the leukemic blasts. In about 2-5% of leukemias, blasts share immunophenotypic features of both lymphoid and myeloid lineages. In international retrospective study we showed superior overall survival in patients treated according to lymphoid type of protocol compared to patients treated to myeloid type of protocol, especially in cases with CD19 positivity on the blasts. Another type of the plasticity and diagnostic uncertainty in leukemia is ALL with early switch to monocytic lineage. About 8% of B cell precursor ALL underwent monocytic switch in our consecutive cohort. This phenomenon is more common among DUX4r, PAX5-P80R and ZNF384r leukemias. Discrepancy between minimal residual disease (MRD) measured by flow cytometry and quantitative assessment of immunoreceptor rearrangements method occurs because of the loss of B-lymphoid markers. We investigated transdifferentiation process by mass cytometry. By the multilabel panel we were able to determine the sequence of changes in proteins and transcription factors by new tviblindi algorithm. Targeted treatment, such as...
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Myeloid lineage involvement in BCR/ABL-positive acute lymphoblastic leukaemia
Hovorková, Lenka ; Zuna, Jan (advisor) ; Mikyšková, Romana (referee)
The Philadelphia chromosome has been discovered in 1960. This chromosomal aberration was mistakenly associated only with chronic myeloid leukaemia (CML) for decade. However, this type of translocation including chromosomes 9 and 22 was found in patients with different type of neoplasia - acute lymphoblastic leukaemia (ALL). Different lineage involvement has been found in these two types of leukaemia. Whereas in Ph-positive ALL, the Philadelphia chromosome is restricted to the lymphoid lineage, in CML patients mostly myeloid cells are those being Ph-positive. Hence it seems quite trivial to distinguish between ALL and CML. But there is a phase of CML called lymphoid blast crisis which is indistinguishable from ALL. The possibility of distinguishing between CML in lymphoid blast crisis and ALL would inhere in determining myeloid lineage involvement. Actually it had been shown that some patients with Ph+ ALL have involved also a myeloid lineage. Different types of treating protocols are used in CML and ALL. In addition, prognoses for both types of leukaemia are different. Thus it is crucial to distinguish between this two disorders and revealing of any difference can impact the treatment outcome of above mentioned malignancies. Detection of minimal residual disease according to involvement of myeloid or CD34+...
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Leukaemias with BCR/ABL fusion gene.
Hovorková, Lenka ; Zuna, Jan (advisor) ; Zemanová, Karla (referee)
Philadelphia (Ph) chromosome, as a result of reciprocal translocation, is in majority of cases connected to two types of leukaemia - chronic myelogenous (CML) and acute lymphoblastic (ALL). The translocation occurs within large intronic sequences of BCR and ABL genes. The breakpoints are specific for individual patient and may be used as a target for monitoring of leukemic burden (MRD, minimal residual disease) during the treatment. In general, MRD is an important prognostic factor, which influences the treatment intensity. Two standardized methods are currently used for its monitoring. The first one is based on the detection of clonal specific Immunoglobulin and/or T-cell receptor genes rearrangements (and thus cannot be used for CML cases) at the DNA level, the second one utilizes detection of the BCR/ABL fusion gene at the mRNA level. Our aim was to optimize and standardize the process to find individual patient breakpoints on Ph chromosome and to use it for MRD quantification. We found the breakpoint in 80 % cases. The MRD data from 15 patients obtained by our method were compared to the levels obtained by standard methods (Ig/TCR and BCR/ABL transcript quantification). In all but 1 patient we found significant discrepancies, raising the questions about leukemic origin and the most accurate method for...
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The use of novel technologies in the identification of unique molecular markers for minimal residual disease assessment in acute leukemia patients
Jančušková, Tereza ; Peková, Soňa (advisor) ; Jarošová, Marie (referee) ; Lysák, Daniel (referee)
Acute leukemias (AL) comprise a heterogeneous group of hematologic malignancies, and individual patient responses to treatment can be difficult to predict. Monitoring of minimal residual disease (MRD) is thus very important and holds great potential for improving treatment strategies. Common MRD targets include immunoglobulin heavy chain or T-cell receptor gene rearrangements, recurrent cytogenetic abnormalities and mutations in important hematological genes. Whereas in the majority of adult acute lymphoblastic leukemia patients a suitable MRD target can be identified, in adult acute myeloid leukemia patients well-characterized targets are found in only half of cases. The identification of new specific molecular markers of leukemic blasts for MRD assessment, particularly in AML patients, is therefore highly desirable. Our aim was to develop a flexible strategy for mapping of cytogenetically identified unique clone-specific abnormalities down to the single nucleotide level and, based on the sequence, design a specific real-time PCR assay for MRD assessment in AL patients without any previously described MRD marker. Using a combination of cytogenetic (chromosome banding, chromosome microdissection), molecular cytogenetic (mFISH, mBAND) and molecular biological (next- generation sequencing, long-range...
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The use of novel technologies in the identification of unique molecular markers for minimal residual disease assessment in acute leukemia patients
Jančušková, Tereza
Acute leukemias (AL) comprise a heterogeneous group of hematologic malignancies, and individual patient responses to treatment can be difficult to predict. Monitoring of minimal residual disease (MRD) is thus very important and holds great potential for improving treatment strategies. Common MRD targets include immunoglobulin heavy chain or T-cell receptor gene rearrangements, recurrent cytogenetic abnormalities and mutations in important hematological genes. Whereas in the majority of adult acute lymphoblastic leukemia patients a suitable MRD target can be identified, in adult acute myeloid leukemia patients well-characterized targets are found in only half of cases. The identification of new specific molecular markers of leukemic blasts for MRD assessment, particularly in AML patients, is therefore highly desirable. Our aim was to develop a flexible strategy for mapping of cytogenetically identified unique clone-specific abnormalities down to the single nucleotide level and, based on the sequence, design a specific real-time PCR assay for MRD assessment in AL patients without any previously described MRD marker. Using a combination of cytogenetic (chromosome banding, chromosome microdissection), molecular cytogenetic (mFISH, mBAND) and molecular biological (next- generation sequencing, long-range...
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Circulating tumor cells in breast cancer patients
Bielčiková, Zuzana ; Zemanová, Milada (advisor) ; Gürlich, Robert (referee) ; Fínek, Jindřich (referee)
Circulating tumor cells (CTCs) represent a systemic phase of the localised cancer disease. They can be distinguished and enriched from the peripheral blood and so from the surrounding leukocytes by either physical properties (e.g., density and size) or biological properties (e.g., expression of epithelial proteins such as EpCAM or cytokeratins) and are usually further characterized by immunostaining or RT-PCR assays. Selecting patients with the risk of disease relaps at the time of diagnosis is crucial for clinicians in deciding who should, and who should not, receive adjuvant chemotherapy. We know that CTCs are strong prognostic factor in patients with metastatic as well as localized breast cancer (BC). It is also known that the prognostic power of circulating tumor cells in women with BC is independent from the standard prognostic indicators. Testing of CTCs known recently as "liquid biopsy" could be informative not only as predictor of the disease relapse, but also as the predictor of therapy effectiveness. The clinical use of CTCs must be strictly encouraged by clinical trials results. Monitoring of CTCs in time could zoom in the mechanism of therapy resistance and/or may provide the identification of new druggable targets. The purpose of my work was therefore to assess the CTCs positivity rate...
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The use of novel technologies in the identification of unique molecular markers for minimal residual disease assessment in acute leukemia patients
Jančušková, Tereza
Acute leukemias (AL) comprise a heterogeneous group of hematologic malignancies, and individual patient responses to treatment can be difficult to predict. Monitoring of minimal residual disease (MRD) is thus very important and holds great potential for improving treatment strategies. Common MRD targets include immunoglobulin heavy chain or T-cell receptor gene rearrangements, recurrent cytogenetic abnormalities and mutations in important hematological genes. Whereas in the majority of adult acute lymphoblastic leukemia patients a suitable MRD target can be identified, in adult acute myeloid leukemia patients well-characterized targets are found in only half of cases. The identification of new specific molecular markers of leukemic blasts for MRD assessment, particularly in AML patients, is therefore highly desirable. Our aim was to develop a flexible strategy for mapping of cytogenetically identified unique clone-specific abnormalities down to the single nucleotide level and, based on the sequence, design a specific real-time PCR assay for MRD assessment in AL patients without any previously described MRD marker. Using a combination of cytogenetic (chromosome banding, chromosome microdissection), molecular cytogenetic (mFISH, mBAND) and molecular biological (next- generation sequencing, long-range...
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The use of novel technologies in the identification of unique molecular markers for minimal residual disease assessment in acute leukemia patients
Jančušková, Tereza ; Peková, Soňa (advisor) ; Jarošová, Marie (referee) ; Lysák, Daniel (referee)
Acute leukemias (AL) comprise a heterogeneous group of hematologic malignancies, and individual patient responses to treatment can be difficult to predict. Monitoring of minimal residual disease (MRD) is thus very important and holds great potential for improving treatment strategies. Common MRD targets include immunoglobulin heavy chain or T-cell receptor gene rearrangements, recurrent cytogenetic abnormalities and mutations in important hematological genes. Whereas in the majority of adult acute lymphoblastic leukemia patients a suitable MRD target can be identified, in adult acute myeloid leukemia patients well-characterized targets are found in only half of cases. The identification of new specific molecular markers of leukemic blasts for MRD assessment, particularly in AML patients, is therefore highly desirable. Our aim was to develop a flexible strategy for mapping of cytogenetically identified unique clone-specific abnormalities down to the single nucleotide level and, based on the sequence, design a specific real-time PCR assay for MRD assessment in AL patients without any previously described MRD marker. Using a combination of cytogenetic (chromosome banding, chromosome microdissection), molecular cytogenetic (mFISH, mBAND) and molecular biological (next- generation sequencing, long-range...
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Leukaemias with BCR/ABL fusion gene.
Hovorková, Lenka ; Zuna, Jan (advisor) ; Zemanová, Karla (referee)
Philadelphia (Ph) chromosome, as a result of reciprocal translocation, is in majority of cases connected to two types of leukaemia - chronic myelogenous (CML) and acute lymphoblastic (ALL). The translocation occurs within large intronic sequences of BCR and ABL genes. The breakpoints are specific for individual patient and may be used as a target for monitoring of leukemic burden (MRD, minimal residual disease) during the treatment. In general, MRD is an important prognostic factor, which influences the treatment intensity. Two standardized methods are currently used for its monitoring. The first one is based on the detection of clonal specific Immunoglobulin and/or T-cell receptor genes rearrangements (and thus cannot be used for CML cases) at the DNA level, the second one utilizes detection of the BCR/ABL fusion gene at the mRNA level. Our aim was to optimize and standardize the process to find individual patient breakpoints on Ph chromosome and to use it for MRD quantification. We found the breakpoint in 80 % cases. The MRD data from 15 patients obtained by our method were compared to the levels obtained by standard methods (Ig/TCR and BCR/ABL transcript quantification). In all but 1 patient we found significant discrepancies, raising the questions about leukemic origin and the most accurate method for...
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Immunoglobulin genes rearrangement and minimal residual disease monitoring in B-lymphoproliferative disease.
Lokvenc, Milan ; Kalinová, Markéta (advisor) ; Krulová, Magdaléna (referee)
Malignant lymphomas are tumors arising by clonal proliferation of lymphocytes stopped at a specific stage of differentiation. All tumor cells arising from the original clone thus share the same characteristics and that can be used in their detection. Finding a suitable molecular marker of tumor cells is an essential step not only to disease diagnosis, but also for monitoring of minimal residual disease. Minimal residual disease is defined as the subclinical disease level, which malignant cells are not detectable for conventional cytological methods during the therapy. These residual cells can cause relapse. The main goals of the diploma thesis are a detection and analysis of immunoglobulin genes rearrangement and chromosomal translocation t(11; 14) in the MTC region, and a development and optimization of RQ-PCR system for detection of minimal residual disease. Quantification of clonal rearrangement or chromosomal translocation allows the detection of minimal residual disease level in patients with malignant lymphomas. Clonal immunoglobulin genes rearrangement or characteristic chromosomal translocation were analyzed in 19 patients with malignant lymphomas. There were analyzed individual gene segments, N-region and combination variability in immunoglobulin genes rearrangement. There was developed...
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