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Circulating biomarkers in colorectal cancer and their application in diagnosis and prognosis
Červená, Klára ; Vymetálková, Veronika (advisor) ; Boublíková, Ludmila (referee) ; Václavíková, Radka (referee)
Despite all the advances in the field of clinical and molecular oncology, the numbers related to the incidence and mortality of colorectal cancer (CRC) remain at unacceptable levels. In recent years, liquid biopsy consisting of circulating biomarkers has come to the forefront of research, offering many advantages over conventional biopsy, such as providing timely information on tumor heterogeneity and the ease of repeated sampling. This dissertation thesis aimed to identify novel candidate circulating biomarkers from microRNAs, long non-coding RNAs, and cell-free DNA that could be used for earlier diagnosis, better prognosis, or prediction of therapy response of CRC patients and thus further advance personalized medicine. The main results of this work are: 1) Circulating microRNAs in plasma (miR-122-5p and miR- 142-5p) can distinguish patients with rectal cancer and cancer-free individuals and could predict therapy response in patients (both in primary and metastatic CRC patients). 2) Gene amplification of the long non-coding RNA MALAT1 can represent an important step in the transition of healthy mucosa to adenoma tissue. Plasma MALAT1 is overexpressed in patients with colorectal adenomas and CRC patients compared to cancer-free individuals and has the potential as a predictive biomarker for CRC...
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A role of microRNAs in the regulation of hepatic drug-metabolizing enzymes
Sedlmajer, Štěpán ; Smutný, Tomáš (advisor) ; Matoušková, Petra (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Štěpán Sedlmajer Supervisor: PharmDr. Tomáš Smutný, Ph.D. Title of diploma thesis: A role of microRNAs in the regulation of hepatic drug-metabolizing enzymes The liver is the main biotransformation organ in the body. Cytochromes P450 and conjugation enzymes are essential enzymes in the metabolism of drugs and other xenobiotics. Recently, there is growing evidence of post-transcriptional regulation of these enzymes through microRNA molecules. MicroRNAs are epigenetic regulators of expression, which usually bind to fully or partially complementary sequences within the 3'UTR (3' untranslated) regions of mRNA molecules. MicroRNAs have a role in interindividual variability of expression and activity of metabolic enzymes. Understanding their role and mechanisms of action may contribute to the development of new drugs and tailored pharmacotherapy. The work summarizes current selected achievements in the research on regulation of mainly hepatic cytochromes P450 and conjugation enzymes through microRNAs. The impact of RNA editing, single nucleotide polymorphisms and pseudogenes is also described.
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The role of circulating microRNAs in the therapy response prediction in colorectal cancer patients.
Landecká, Aneta ; Vymetálková, Veronika (advisor) ; Hlaváč, Viktor (referee)
Colorectal cancer (CRC) is one of the most common cancers both in the world and in the Czech Republic. Predispositions for the development of CRC include genetic and epigenetic changes, as well as environmental and microenvironmental factors. These tumours often respond very well to treatment, especially in the early stages, but some patients experience early recurrence of the disease. As the incidence of CRC has not declined in recent years, this is a current problem requiring a new approach aimed at improving diagnosis, survival and quality of life of patients with CRC. For this reason, liquid biopsy, which is a minimally invasive approach to the patient and allows real-time monitoring of changes in the body, is increasingly gaining prominence. One of the biomarkers that can be detected by liquid biopsy are small non-coding RNA molecules - microRNAs (miRNAs). In this thesis, the gene expression of two miRNAs, namely miR-122-5p and miR-142-5p, was analyzed in plasma and tissues of CRC patients and in plasma of a control group of healthy blood donors. In our study, we identified significant changes in the expression levels of both miRNAs in CRC patients compared to healthy cancer- free subjects. Specifically, higher expression levels of both miRNAs were observed in CRC patients compared to the...
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The biological significance of changes in the vascular wall and atherosclerotic plaque for the development of atherosclerotic disease of the coronary arteries
Horváth, Martin ; Hájek, Petr (advisor) ; Poledne, Rudolf (referee) ; Kovárník, Tomáš (referee)
Acute complications of atherosclerosis are typically caused by arterial occlusion due to acute thrombosis forming over a ruptured vulnerable atherosclerotic plaque (VP). Early identification of such VP prior to their rupture could help prevent these events. At the same time, methods for assessing cardiovascular risk are focused on measures at the population level and are not sensitive and specific enough to assess the risk of individual patients. We therefore focused on the possibilities of in vivo detection of VP using biomarkers and invasive imaging methods. First, we focused on the detection of microRNAs (miRs), which have been investigated in recent years as promising biomarkers for a number of diseases, including atherosclerosis. We determined miR levels using quantitative polymerase chain reaction in peripheral venous blood samples from patients in very early phase of ST-elevation myocardial infarction (STEMI), which served as the closest clinical model of acute VP rupture. The results led to the identification of two miRs (miR-331 and miR-151-3p) that were deregulated in STEMI and could be biomarkers of VP. In the next part of the research, we dealt with the possibilities of invasive imaging of VP using intravascular ultrasound and near- infrared spectroscopy (IVUS and NIRS). We confirmed...
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Small extracellular vesicles as microRNA carriers and their role in neural cell regeneration
Šprincl, Vojtěch ; Romanyuk, Natalyia (advisor) ; Kriška, Ján (referee)
Acute spinal cord injury is a serious type of injury, the treatment of which still represents a challenge for contemporary medicine. Neural stem cells (NSCs) transplantation is one of many promising ways to contribute to the regeneration of damaged tissue. NSCs communicate with the rest of the tissue by means of small extracellular vesicles (sEVs), in which their regenerative potential is thus assumed. The aim of this thesis is to verify the antiapoptotic effect of sEVs isolated from the culture medium of two types of NSCs in an rat in vitro model of spinal cord injury. To meet this goal, different methods of isolating sEVs from the culture medium were tested. Subsequently, sEVs were characterized according to their size and the presence of surface markers. This thesis includes an PCR analysis of the cargo of sEVs, which showed an abundance of neuroprotective and antiapoptotic miRNAs. Fluorescent staining of sEVs proved that sEVs penetrate into the cytoplasm of stem cells. Finally, sEVs were applied to a rat in vitro model of spinal cord injury and their neuroprotective effect was demonstrated using the immunoblotting method. Keywords Small extracellular vesicles, exosomes, acute spinal cord injury, regeneration of nervous tissue, miRNA, microRNA, neural stem cells
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The role of miRNA in injury and regeneration of spinal cord tissue
Šprincl, Vojtěch ; Romanyuk, Natalyia (advisor) ; Mrózková, Petra (referee)
MicroRNAs are small non-coding RNA molecules of a length about 20-24 nucleotides, that regulate gene expression post-transcriptionally. They interfere mRNA molecules via base- pairing with complementary sequences. Recently it was shown that they play an important role in injury and regeneration of nervous tissue. The aim of this bachelor thesis is to describe possible role of miRNAs in central nervous system injury with focus on spinal cord injury.
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Relation between cardiovascular microRNAs and pregnancy-related complications
Dalecká, Linda ; Hromadníková, Ilona (advisor) ; Daňková, Pavlína (referee)
During the pregnancy, there are many complications, which can affect a fetal development and eventually, its or mother's life. Pre-eclampsia is one of these complications. It is a hypertensive disorder, which appears during the pregnancy. Another example of these complications is an intrauterine growth restriction. It is a condition, when the fetus is not able to reach its genetical growth potential. Both of those pathological disorders are accompanied by changes in microRNA gene expression in placenta, for example miR-16, miR-21, miR-210. Knowledge about these changes in gene expression could represent unique instruments in the field of noninvasive prenatal diagnosis of these disorders. This could be benefitial due to the fact, that both of these disorders are responsible for increasing maternal and perinatal morbidity and mortality. This work focused on microRNAs, their expression in aformentioned disorders and benefits, which could bring in diagnostics. In this work these two disorders, characteristics of microRNAs and their biogenesi are described. MicroRNAs are interesting for us as potential biomarkers for noninvasive prenatal diagnostics becouse they are present in body fluids, such as plasma, breast milk or amniotic fluid and they are not subject of rapid degradation. Key words:...
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The role of microRNAs in lymphomas with a focus on miR-155
Hušková, Hana ; Stopka, Tomáš (advisor) ; Svoboda, Petr (referee)
MicroRNAs (miRNAs) are 19-25 nucleotide noncoding RNAs which regulate the expression of target mRNAs at both posttranscriptional and translational level. The physiological functions of miRNAs include development, differentiation, cell cycle regulation and apoptosis. miRNA deregulation has been found in various human diseases, including lymphoproliferative disorders. This Bachelor thesis provides introduction to delineate roles of miRNAs in normal hematopoiesis and cites recent publications on miRNAs in lymphomas with a focus on the role of miR-155. Key words microRNA, hematopoiesis, lymphoma, miR-155
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Transcriptional regulation of miR-17-92 microRNA cluster during macrophage differentiation.
Rybářová, Jana ; Stopka, Tomáš (advisor) ; Pospíšek, Martin (referee)
miR-17-92 cluster (Oncomir1) encodes seven microRNAs (miRNA, miR) regulating many biological processes including proliferation, differentiation or apoptosis. Overexpression of microRNAs encoded by miR-17-92 cluster is found in a number of tumors including acute and chronic myeloid leukemias (Dixon-McIver et al., 2008; Li et al., 2008; Venturini et al., 2007). Myeloid progenitors express miR-17-92 cluster at a high level, while macrophage differentiation associates with its downregulation. Our laboratory found, that miR-17-92 cluster is repressed by transcription factor Early growth response 2 (Egr2) upon differentiation of primary myeloid PUER progenitors, induced with transcription factor PU.1. Aim of this thesis is to further test the abovementioned data by preparing a reporter vectors set, carrying various fragments of miR-17-92 putative promoter, which enables us to study regulation of transcription of miR-17-92 cluster. This task complicated by presence of increased GC content of the miR-17-92 promoter was successfully accomplished resulting in amplification of eight fragments containing the various parts of miR-17-92 promoter including region -3.3 to 0 kb relative to the start of miR-17-5p sequence, that were inserted into pGL3 reporter vector. Transfection of pGL3 reporter vector carrying...
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Diagnostic and prognostic impact of miR-122 and miR-142 in colorectal cancer
Kalkušová, Kateřina ; Červená, Klára (advisor) ; Král, Jan (referee)
Colorectal carcinoma is one of the most frequent cancers and it is also one of the most common causes of cancer related death. It is often diagnosed at a late stage which is associated with a worse prognosis. Therefore, there is an effort to identify new biomarkers that allow earlier diagnosis. These biomarkers could predict prognosis of disease and patient's response to treatment. Short noncoding RNAs - microRNA - appears to be promising candidates, these molecules are involved in many cellular processes through RNA interference. The aim of this thesis is to summarize knowledge about application of miR-122 and miR-142 as diagnostic and prognostic biomarkers for colorectal cancer. Keywords: microRNA, biomarkers, colorectal cancer, diagnostics, prognosis
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