PU.1 downregulation within haematopoietic stem and progenitor cells (HSPCs) is the primary mechanism for the development of acute myeloid leukaemia (AML) in mice with homozygous deletion of the upstream regulatory element (URE) of PU.1 gene. p53 is a well known tumor suppressor that is often mutated in human haematologic malignancies including AML and adds to their aggressiveness; however its genetic deletion does not cause AML in mouse. Deletion of p53 in the PU.1ure/ure mice (PU.1ure/ure p53-/- ) results in more aggressive AML with shortened overall survival. PU.1ure/ure p53-/- progenitors express significantly lower PU.1 levels. In addition to URE deletion we searched for other mechanisms that in absence of p53 contribute to decreased PU.1 levels in PU.1ure/ure p53-/- mice. We found involvement of Myb and miR-155 in downregulation of PU.1 in aggressive murine AML. Upon inhibition of either Myb or miR-155 in vitro the AML progenitors restore PU.1 levels and lose leukaemic cell growth similarly to PU.1 rescue. The MYB/miR-155/PU.1 axis is a target of p53 and is activated early after p53 loss as indicated by transient p53 knockdown. Furthermore, deregulation of both MYB and miR-155 coupled with PU.1 downregulation was observed in human AML, suggesting that MYB/miR-155/PU.1 mechanism may be involved...

Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical sciences Candidate: Bc. Monika Šmídlová Supervisor: RNDr. Eva Novotná, Ph.D. Title of diploma thesis: Effect of selected cytostatics for the treatment of leukemia on the activity of human carbonyl reducing enzymes Key words: reductases, leukemia, cytostatics, inhibition Anthracycline antibiotics, especially daunorubicin, are widely used for the treatment of acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL). Although the efficacy of these drugs is high, treatment is still limited due to cardiotoxicity and tumor cell resistance to anthracyclines. Mechanisms that contribute to the formation of anthracycline resistance include metabolic biotransformation (reduction) to less efficient secondary alcohols. The reduction is calatyzed by carbonyl reducing enzymes belonging to aldo-keto reductase (AKR) and short chain dehydrogenase/reductase (SDR) superfamilies. The discovery of AKR and SDR inhibitors could help to overcome anthracycline resistance and also reduce cardiotoxicity caused by these drugs. The aim of the diploma thesis was to find out whether all-trans-retinoic acid, cyclophosphamide, cytarabine, cladribine and prednisolone are able to inhibit anthracycline reductases AKR1A1, AKR1B10, AKR1C3, AKR7A2...

Apoptosis serves as a natural barrier to cancer development, and the resistance to apoptosis represents one of the key capabilities acquired during tumor development or progression. Impairment of the intrinsic apoptotic pathway exemplifies one of the established mechanisms of constitutive or acquired drug resistance. As most of the currently used cytotoxic drugs initiate tumor cell death by direct or indirect triggering of the intrinsic apoptotic pathway, impairment of the intrinsic pathway is associated with therapy failure. Targeting of the death receptors, however, enables induction of apoptosis even in the chemotherapy resistant cancer cells. TRAIL is a death ligand belonging to the TNFα superfamily that specifically kills tumor cells while sparing healthy tissues. Much enthusiasm has been generated for TRAIL as a highly promising targeted anti-cancer agent. However, many primary tumors have been shown to be TRAIL resistant. In attempt to overcome such an intrinsic TRAIL resistance a wide array of agents have been shown to sensitize tumor cells to TRAIL. Previous studies reported that roscovitine, a cyclin-dependent kinase inhibitor, sensitized various solid cancer cells to TRAIL. In this study we analyzed the sensitivity of diverse hematologic malignancies to TRAIL-induced apoptosis and measured the...

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...

Acute myeloid leukemia (AML) is a hematopoietic malignancy characterized by great heterogeneity and clonal nature. In recent years, rapidly evolving next-generation sequencing methods provided a deep insight into the mutational background of AML. It was shown that ~ 44 % of AML patients harbor mutations in genes that regulate DNA methylation. So far, many researchers have tried to evaluate the prognostic significance of DNA methylation changes in AML, however, due to a great inconsistency in these studies, none of the reported markers were implemented into clinical practice. The aim of this work was to further investigate the DNA methylation changes in AML patients with specific mutations and their prognostic effect. Next, we wanted to develop a new approach for a complex evaluation of prognostically significant DNA methylation aberrations. In our first project, we assessed the overall DNA methylation, hydroxymethylation, and gene expression in AML patients with mutations in either DNMT3A or IDH1/2 or their combinations. We discovered that each genetic aberration is connected with a distinct pattern of DNA hydroxy-/methylation changes that are not entirely reflected in altered gene expression. Patients with mutations in both genes exhibited a mixed DNA methylation profile most similar to healthy...

Klasické schéma vývoje hematopoetických buněk předpokládá časné oddělení lymfoidního a myeloidního prekurzoru. V poslední době jsou navrhovány složitější modely, které předpokládají větší flexibilitu hematopoezy a navrhují existenci progenitorů s lymfoidním i myeloidním potenciálem. Akutní hybridní leukémie jsou malignity, které podle různých kritérií nelze jednoznačně zařadit k lymfoidní nebo k myeloidní linii a jejichž chování spíše dává za pravdu novým modelům hematopoezy. Předkládaná práce se zabývala především výzkumem dětských leukémií s přesmykem z lymfoidní do myeloidní linie během indukční léčby. Jedná se o rozsáhlý projekt, v jehož rámci si diplomová práce si kladla za úkol určit liniové zařazení leukemických blastů pomocí detekce přestaveb genů pro imunoglobuliny a T-buněčné receptory (TCR). Potvrdili jsme, že myeloidní buňky derivované v průběhu léčby pochází u všech pacientů z původního lymfoidního klonu. Dále jsme u těchto případů zkoumali expresi vytipovaných genů ve srovnání s běžnými druhy leukémií. Třetí částí práce byl výzkum prognostického významu přítomnosti přestaveb TCR (a tedy příslušnosti k lymfoidní linii) u leukémií z T-lymfoidní řady.

Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Jesika Štorkánová Supervisor: RNDr. Eva Novotná, Ph.D. Title of diploma thesis: Study of the cytotoxicity of selected chemotherapeutics for the treatment of leukemia in human tumor cell lines Leukemia represents a diverse group of malignant diseases with a hematopoietic disorder with different prognoses. As the incidence of patients with leukemia is increasing, is an effort to establish the treatment that will lead to successful therapy. One of the basic approaches to the treatment of leukemias is chemotherapy. Today it is known that the effectiveness of chemotherapy is influenced by a number of factors which can significantly affect the treatment strategy and thus decide on the outcome of the treatment itself. An important approach in chemotherapy is the selection of cytostatics with maximum efficacy for oncological disease and elimination cytostatics to which the cells are resistant based on the findings in in vitro conditions. The aim of this diploma thesis was to determine the inhibitory effects of in vitro selected chemotherapeutics in cell tumor lines. For determine the inhibitory effect, HCT116, HepG2 and HL-60 cell lines were selected using a colorimetric method based on the...

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...

THE INFLUENCE OF MOTIVATIONAL ELEMENTS IN PAEDIATRIC PHYSIOTHERAPY FOCUSED ON THE PATIENTS WITH ACUTE LYMPHOBLASTIC LEUKEMIA - PILOT STUDY Abstract The efficacy of acute lymphoblastic leukemia (ALL) treatment in childhood is still increasing and the quality of life of these children is starting to be the focus of interest. The physiotherapy affects in preventive and reactive way the late effects of treatment which may reduce the quality of life. An insufficient motivation of children can be a reason of a reduced adherence to a physiotherapeutic intervention. The goal of this study was to ascertain the influence of the motivational elements in the paediatric physiotherapy in the improvement of motor functions, the quality of life, the motivation to the exercise and the frequency of exercise. There were 9 patients diagnosed with ALL in the maintenance phase of treatment (average age 7,3 years, age range 5,2 - 10,1, 5 girls and 4 boys). All probands underwent a 6- weeks-excercise programme that contains the exercise from the DNS method, yoga for children and stretching. The assessment was performed by Bruninks-Oseretsky Test (BOT2), 6 minute walking test (6MWT), goniometric measurement of ankle joint dorsiflexion, Pediatric Quality of Life Inventory (PedsQL), Intrinsic Motivation Inventory (IMI) and the...

The theoretical part of the thesis summarizes general information about the human TP53 gene and p53 protein, which is encoded by this gene. There is also dealt with the transcriptional variants - p53 isoforms. The experimental part is focused on the detection of isoform p53 and its shorter, yet undescribed form. The starting material is peripheral blood of patients from University Hospital Brno, from which RNA was isolated. Subsequently, RNA was transcribed by reverse transcription into cDNA which was amplified by polymerase chain reaction (PCR). Experimental measurements demonstrate that p53 occurs in all the B-lymphocytes of patients with chronic lymphocytic leukemia. It also demonstrats the existence of a shorter form of p53.