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Study of placental specific microRNA expression in pacients with spontaneous preterm birth and preterm prelabor rupture of membranes
Vintrová, Iva ; Hromadníková, Ilona (advisor) ; Daňková, Pavlína (referee)
MicroRNAs (miRNAs) are small non-coding RNAs with a length of 18 to 25 nucleotides playing a pivotal role in post-transcriptional regulation of gene expression. There are miRNAs whose expression is limited to a certain tissue type and diseases which are characterized by a unique miRNA expression profile. I assumed spontaneous preterm birth (PTB) and preterm prelabor rupture of membranes (PPROM) would be characterized by a unique miRNA expression profile. I observed the gene expression of 15 placental specific miRNAs (miR-512-5p, miR-515-5p, miR-516b-5p, miR-517-5p, miR-518b, miR-518f-5p, miR-519a-5p, miR-519d-3p, miR-519e- 5p, miR-520a-5p, miR-520h, miR-524-5p, miR-525-5p, miR-526a and miR-526b-5p) in placental tissue of pacients with PTB, PPROM and women with term in labor pregnancies (FG). PTB group consisted of 24 pacients, PPROM group of 75 pacients and FG group of 20 pacients. Quantitative real-time PCR was used to quantify gene expression. In the group of PTB pregnancies I identified 3 significantly upregulated miRNAs (miR-516b-5p, miR-519d-3p and miR-524-5p) and 4 miRNAs (miR-518b, miR-519a-5p, miR-520h and miR-526a) with a trend to upregulation compared to controls (FG). In the group of PPROM pregnancies I identified 3 miRNAs (miR-519d-3p, miR-520h and miR-256b-5p) with a trend to...
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Epigenetické regulace u autoimunitních onemocnění se zaměřením na revmatoidní artritidu
Horková, Veronika ; Daňková, Pavlína (advisor) ; Hušáková, Markéta (referee)
Exact cause of rheumatoid arthritis, as well as other autoimmune diseases has not been identified yet. In last twenty years, epigenetics showed a new face of immune system. DNA methylation, modification of histones - proteins around which DNA is wrapped, or interference of small RNA sequences - microRNAs, these all are heritable changes outside the DNA sequence that provide another component involved in autoimmunity. Presented epigenetic mechanisms alter gene expression and thus facilitate production of pro- inflammatory factors leading to autoimmune reactions. Moreover, genes regulating apoptosis are also frequently targeted by epigenetic modifications. Not only these mechanisms provide another level of immune defense, they also explain higher female susceptibility to autoimmune diseases and the influence of environment on pathogenesis of these diseases.
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Role of microRNA in regulations of circadian rhythms and tumorigenesis
Balounová, Kateřina ; Pácha, Jiří (advisor) ; Červená, Kateřina (referee)
MicroRNAs (miRNAs) are ~22nt long single-strand RNA found in all groups of organisms, where they affect biochemical, physiological and behavioral pathways by regulation of protein expression. Regulation of protein expression is mediated by silencing mRNA of target genes in one of two processes, translation repression or degradation of mRNA. Changed expression of miRNA can lead to aberrant regulatory pathways resulting in various pathophysiological conditions like cardiovascular diseases, cancer or neurological disorders. MiRNA can play a role in cancer both as an oncogen or as a tumor suppressor, and it is tissue and cancer-type specific. In colorectal cancer miRNAs downregulate or upregulate signaling pathways including key processes involved in cancer development, like proliferation, cell cycle, apoptosis and metastasis formation. Circadian clock in mammals synchronizes cellular and physiological processes by transcriptional-translational feedback loops. Not only miRNAs regulate the levels of key clock genes and clock controlled genes, but also a number of miRNAs exhibit circadian expression. Therefore aberrant circadian rhythms increase risk of colorectal cancer also by altered expression of miRNAs. The main aim of the thesis was to identify miRNAs, which regulate both tumorigenesis and circadian...
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The Role of oncogenic microRNA - 155 and proto - oncogen MYB in chronic lymphocytic leukemia
Vargová, Karina
(EN) Chronic lymphocytic leukemia (B-CLL) represents a disease of mature-like B-cells. Due to failed apoptosis but also due to enhanced proliferative signals, the leukemic B-cells accumulate in the peripheral blood, bone marrow, lymph nodes and spleen. The clinical course of B-CLL is very heterogeneous; in some patients B-CLL progresses very rapidly into an aggressive form. Such patients need therapy sooner while in other patients with indolent B-CLL the onset of therapy takes years. Several standard prognostic and disease progression markers are used for disease staging and monitoring, however a reliable marker that will suggest when to start therapy is unknown. Expression of small, non-coding microRNAs is often deregulated and represent important prognostic markers in variety of cancers including leukemia. Hence in our study we concentrated to miR-155, an important molecule regulating differentiation of hematopoietic cells, inflammation process and antibody production. Its aberrant expression was described in Hodgkin`s as well as in non-Hodgkin`s lymphoma, including indolent lymphoproliferations like B-CLL. Our results confirmed elevated levels of both, primary miR-155 transcript and mature form of miR-155 in our B-CLL patient samples (N=239). The aberrant expression of miR-155 in B-CLL samples...
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Delineating aggressiveness of acute myeloid leukemia in a mouse model carrying mutations of Spil (PU.1) and Trp53.
Bašová, Petra
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...
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Role onkogenní mikroRNA-155 a proto-onkogenu MYB u chronické lymfatické leukémie
Vargová, Karina ; Stopka, Tomáš (advisor) ; Móciková, Heidi (referee) ; Trka, Jan (referee)
(EN) Chronic lymphocytic leukemia (B-CLL) represents a disease of mature-like B-cells. Due to failed apoptosis but also due to enhanced proliferative signals, the leukemic B-cells accumulate in the peripheral blood, bone marrow, lymph nodes and spleen. The clinical course of B-CLL is very heterogeneous; in some patients B-CLL progresses very rapidly into an aggressive form. Such patients need therapy sooner while in other patients with indolent B-CLL the onset of therapy takes years. Several standard prognostic and disease progression markers are used for disease staging and monitoring, however a reliable marker that will suggest when to start therapy is unknown. Expression of small, non-coding microRNAs is often deregulated and represent important prognostic markers in variety of cancers including leukemia. Hence in our study we concentrated to miR-155, an important molecule regulating differentiation of hematopoietic cells, inflammation process and antibody production. Its aberrant expression was described in Hodgkin`s as well as in non-Hodgkin`s lymphoma, including indolent lymphoproliferations like B- CLL. Our results confirmed elevated levels of both, primary miR-155 transcript and mature form of miR-155 in our B-CLL patient samples (N=239). The aberrant expression of miR-155 in B-CLL samples...
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Delineating aggressiveness of acute myeloid leukemia in a mouse model carrying mutations of Spil (PU.1) and Trp53.
Bašová, Petra ; Stopka, Tomáš (advisor) ; Machová Poláková, Kateřina (referee) ; Zuna, Jan (referee)
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...
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Extracellular microRNAs in hematological malignancies and their use for diagnosis and treatment monitoring
Šulcová, Dominika ; Pospíšil, Vít (advisor) ; Čermák, Vladimír (referee)
MicroRNAs are short non-coding RNAs that negatively regulate gene expression at post-transcriptional level by interfering with mRNA translation and stability. Recently, microRNAs were surprisingly found to be present in various body fluids including blood plasma and serum, cerebrospinal fluid, saliva, milk or urine. These extracellular microRNAs are resistant to RNases and stable in high temperature or pH. Extreme stability of extracellular microRNAs is caused by their association with protective protein complexes (mostly with Argonaute proteins). MicroRNAs are frequently deregulated in cancer and specific tumor- related microRNAs can be also detected in body fluids, indicating that extracellular microRNAs can be used as tumor specific markers. This Bachelor thesis reviews basic principles of microRNA function and biogenesis with focus on extracellular microRNAs and their role in intercellular communication, and it highlights the role of extracellular microRNAs in hematological malignancies and their possible use in diagnosis and treatment.
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Up-regulation of microRNA miR-155 is reflected by low levels of its target mRNA encoding transcription factor PU.1 in primary tumors of human lymphomas
Hušková, Hana ; Stopka, Tomáš (advisor) ; Mráz, Marek (referee)
Lymphomas are heterogenous class of diseases characterized by proliferation of a malignant lymphocyte clone. MicroRNA miR-155 was found to be a key molecule in immune response, namely in inflammation and germinal reaction of B cells. On the other hand, miR-155 can drive lymphoproliferation in mouse and its levels were found to be elevated in certain lymphoma types in human. MiR-155 down-regulates expression of its target gene PU.1, a hematopoietic transcription factor important for B cell differentiation. Expression of the gene encoding miR-155, known as MIR155HG, is controled by several transcription factors, among them MYB, a member of an oncogenic E-box protein family. Levels of MYB itself are controled by microRNA miR-150. In this study, we measured levels of miR-155, PU.1, MYB and miR-150 in lymph nodes of patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (B-CLL/SLL, N=20), diffuse large B-cell lymphoma (DLBCL, N=24), follicular lymphoma (FL, N=29), Hodgkin lymphoma (HL, N=25), marginal zone lymphoma (MZL, N=13), and mantle cell lymphoma (MCL, N=10). We also measured levels of these molecules in lymph nodes with the finding of strong inflammation (N=4). We found that patients of all the diagnoses except of MCL display heterogeneously elevated levels of miR-155 and correspondingly...
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Extracellular microRNAs and their role in pathologies especially in the field of gynecology and obstetrics.
Štěrbová, Monika ; Hromadníková, Ilona (advisor) ; Balušíková, Kamila (referee)
microRNAs (miRNAs) represent a relatively newly discovered group of RNA molecules and they serve to regulate gene expression. In spite of processes of differentiation, proliferation and apoptosis, miRNAs influence the whole biological systems, such as embryogenesis, oncogenesis, and immunity. There have been a number of experiments in recent years concerning diagnoses and predictions of complications during pregnancy, and tumour growth. Extracellular miRNA molecules participating in circulation of patients are used in the non-invasive diagnostics. RNA molecules usually get into the extracellular fluid during the apoptosis process. I chose four diseases, which extracellular miRNA have diagnostic potential - preeclampsia, intrauterine growth retardation, gestational diabetes mellitus and breast cancer - for my work. An aberrant expression of different levels of various extracellular miRNAs has been reported in these diseases but the clinical use of microRNAs in the diagnosis and prediction of those still requires further research and optimization. Keywords: breast cancer, extracellular nucleic acids, fetal growth retardation, gestational diabetes mellitus, microRNA, PCR, preeclampsia
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