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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 Function of the Adaptor Molecules in Leukaemogenesis
Švojgr, Karel ; Zuna, Jan (advisor) ; Filipp, Dominik (referee) ; Zemanová, Zuzana (referee)
Acute lymphoblastic leukaemia is the most common malignancy in childhood. Various acquired and congenital factors are involved in leukemogenesis including aberrant cell signaling. Transmembrane adaptor molecules could play an important role in development and propagation of leukemia. In a first part of our study, we analyzed an expression of adaptor molecules PAG, LAT and NTAL in physiological lymphocyte precursors and in diagnostic samples of different subtypes of childhood acute lymphoblastic leukemia (ALL). In physiological lymphocyte development the expression of adaptor molecules has significant dynamics (increase of LAT and decrease of NTAL in T-lymphocyte development; decrease of PAG in B- lymphocyte development). Similarly, in subtypes of childhood ALL the expression of adaptor molecules is very different. Especially, TAL/AML1 positive acute lymphoblastic leukemia has a unique expression profile of adaptor molecules (high expression of PAG and LAT, low expression of molecule NTAL). In T-cell acute lymphoblastic leukemia the expression of NTAL molecule identifies two groups of patients - those, who respond favourably to initial prednisone treatment, have higher level of NTAL comparing to patients, who respond to prednisone unfavourably. Those patients have low level of NTAL molecule expression. In a...
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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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Etiology of childhood acute leukemia
Burjanivová, Tatiana ; Zuna, Jan (advisor) ; Mihál, Vladimír (referee) ; Haškovec, Cedrick (referee)
Childhood acute leukaemias are a heterogeneous group of malignant diseases. Based on cell origin, clinical manifestations, and molecular/chromosomal changes, we distinguish two main subtypes: acute myeloid leukaemia and acute lymphoblastic leukaemia. Acute lymphoblastic leukaemia (ALL) is the most frequent form of childhood leukaemia. Acute myeloid leukaemia (AML) is predominantly found in adults, being rarer in childhood. In the Czech Republic, the ALL is in childhood diagnosed approximately five times more often compared to AML. Despite the intensive research, aetiology of leukaemia has not been entirely clarified. So far, we only have knowledge of certain risk factors (ionising radiation, some chemicals and viruses) but in the vast majority of cases the aetiopathogenesis has not yet been made clear. Some of the answers may be provided by studies dealing with the presence of (pre)-leukaemic cells in a material archived prior to the clinical onset of the disease. Such are for example the so-called Guthrie cards, the dried blood samples collected immediately after birth and used in screening of the newborns for metabolic disorders. The better availability of material collected before the diagnosis of a secondary leukaemia (originally meant for the follow-up of the primary malignancy) might help us in better...
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