|
|
Host-microbe interactions and its consequences for intestinal inflammation and carcinogenesis
Kejzlarová, Leona ; Kverka, Miloslav (advisor) ; Smrž, Daniel (referee)
A number of physiological and pathological processes, including the transition from chronic inflammation to cancer, are affected by commensal microbes. However, abundance of microbes and ability to produce active metabolites in the intestine depend on environmental factors, particularly diet. Microbes can influence this process in two ways, by producing genotoxic substances that directly damage the epithelium or by stimulating the inflammatory response. The aim of my thesis was to study the interaction among gut microbiota, diet and the immune system with the subsequent influence on the development of colorectal cancer (CRC) in an experimental mouse model. Animals were fed synthetic diets containing either normal amounts of animal protein (17%; KD) or elevated amounts of animal protein (51%; HPD) throughout the experiments. Two weeks after the diets were introduced, intestinal tumors were induced by administering azoxymethane (AOM) and inducing acute inflammation with 2% sodium dextran sulfate one week after AOM injection. At the end of the experiment I evaluated the number of tumors in the colon and the status of the immune response in the intestine, mesenteric lymph nodes and spleen. To study the effect of macrophages, a similar experiment was performed in animals with depleted macrophages using...
|
|
|
The study of tumour DNA virus integrations
Frčková, Tereza ; Saláková, Martina (advisor) ; Šroller, Vojtěch (referee)
Most people perceive viruses primarily as a cause of diseases such as cold, flu or COVID-19. But there are also viruses with oncogenic potential. There are several ways in which viruses contribute to the development of tumors. In the case of human papillomavirus and Merkel cell virus, it is the expression of oncogenes encoded in viral genomes. The virus may be integrated into the host genome, which can also promote the development of carcinogenesis. In this work, the method of detection of integrated papillomavirus sequence by polymerase chain reaction (DIPS PCR) was used to detect the integration breakpoints in human papillomavirus (HPV) in positive cell lines originated from cervical cancer, clinical head and neck cancer samples associated with HPV, and clinical samples of Merkel cell carcinoma. In the case of Merkel cell carcinoma, DIPS PCR method was performed on samples isolated from fresh frozen tissues and from formalin fixed paraffin embedded (FFPE) sections of tumor samples. In the case of tonsillar tumors associated with HPV, only fresh frozen tissues were used. Integration breakpoints were detected in samples from both fresh frozen and FFPE tissues using DIPS PCR method. For the detection of HPV genome integration breakpoints, a new set of primers was tested and optimized on the SiHa...
|
|
|
Terapeutické monoklonální protilátky v nádorovém léčbě
Danišová, Terezie
In recent years, therapy with monoclonal antibodies has been increasingly used in clinical practice. Treatment based on these antibodies has a wide range of advantages over classical therapeutic procedures such as chemotherapy, including reduced side effects. Their greatest advantage is their specificity towards cancer cells, which does not damage surrounding healthy cells. The aim of this compilation work is to summarize and present the molecular basis of tu-mour development and the processes that monoclonal antibodies suppress, stimulate, and contribute to stopping tumour progression. This compilation work provides a basic literary over-view of carcinogenesis at the molecular level, which is necessary for understanding the princi-ples on which monoclonal antibodies function. This work later focuses on monoclonal antibodies, their mechanism of action, and production techniques.
|
|
|
Knockout isoforem metalothioneinu pomocí metody CRISPR-Cas9 u adherentních tkáňových kultur
Duda, Jakub
It is not too long ago, that genome modifications were very complex, or, in some cases, almost impossible to achieve, but with the discovery and description of the CRISPR system in prokaryotes, a lot of breakthroughs came to the human knowledge, and thanks to some of these breakthroughs the CRISPR system has been modified to be used as a genome editing tool in eukaryotic organisms. Genetic modifications could in theory be the key to cancer therapy in modern pharmacy, and this thesis focuses on Metalmetallothionein (MT) proteins, which are commonly found in organisms and are beneficial to the organism (as inhibotors of oxidative stress, or as antioxidants binding heavy metals, for example), but can also be dangerous. Because, according to the isoform, and also the type of tissue, MTs can cause the development of cancer tissue and tumour growth, sometimes because of their presence, in other cases because of their absence. This thesis was focusing on the possible knock-out of all isoforms of MT at once, using CRISPR/Cas9 method, and thereby infucencing one of the very important factors in carcinogenesis. The result of this thesis is the achievement of knock-out of the MT3 isoform.
|
|
|
Study of metabolism air pollutants and mutagens 3-nitrobenzanthrone and 2-nitrobenzanthrone
Čechová, Tereza ; Stiborová, Marie (advisor) ; Martínek, Václav (referee)
Nitroaromatic compounds are mutagenic and carcinogenic substances present in environment. Most of nitroaromatic compounds are potent mutagens in bacterial and mammalian systems. They are also carcinogens causing development of tumors, primarily in the liver, lung and mammary glands. 3-Nitrobenzanthrone (3-NBA, 3-nitro-7H-benz [de] anthracene-7-one) is one of the polycyclic aromatic nitro compounds possesing high toxic effects. 3-NBA is an environmental pollutant present in diesel exhaust and was also detected in soil and in rain water. 2-Nitrobenzanthrone (2-NBA, 2-nitro-7H-benz [de] anthracene-7-one) is an isomer 3-NBA, which also occurs as a pollutant in air. Although the 2-NBA is a weakly toxic substance, its high abundance in air could exhibit a high health risk to humans. This thesis investigates the metabolism of 3-NBA and its isomeric derivate, isomer 2 NBA, under anaerobic and aerobic conditions. To study the metabolism of these compounds, microsomal systems isolated from the liver of rats pretreated with Sudanem I, -naphthoflavone, phenobarbital, ethanol and pregnenolon 16-carbonitrile (PCN), the inducers of cytochromes P450 1A, 2B, 2E1 and 3A, were used. We also used mouse models, a control mouse line (wild type WT) and mice with deleted gene of NADPH:CYP reductase in the liver, thus absenting...
|
|
|
The study of tumour DNA virus intergrations
Frčková, Tereza ; Saláková, Martina (advisor) ; Šroller, Vojtěch (referee)
Most people perceive viruses primarily as the cause of diseases such as cold, flu or COVID-19. But there are also viruses with oncogenic potencial. There are several ways in which viruses provide to the development of tumors. In the case of human papillomavirus and Merkel cell virus, this is the expression of oncogens encoded in viral genomes. The virus may be integrated into the host genome, which can also promote to the development of carcinogenesis. In this work, the method of detection of integrated papillomavirus sequence by polymerase chain reaction (DIPS PCR) was used to detect the integration breakpoints in human papillomavirus (HPV) of positive cell lines originated from cervix cancer, clinical head and neck cancer samples associated with HPV, and clinical samples of cancer from Merkel cells. In the case of Merkel cell carcinoma, the DIPS PCR method was performed on samples isolated from freshly frozen tissue and from cuts of tumor samples stored in paraffin. In the case of tonsil tumors associated with HPV, it was only freshly frozen tissue. Using the DIPS PCR method, integration breakpoints were detected in samples from both freshly frozen tissue and tissue stored in paraffin. For the detection of HPV genome integration breakpoints, a new set of primers was tested, which was optimized on...
|
|
|
The importance of cell-free HPV DNA detection
Milt, Petr ; Saláková, Martina (advisor) ; Horníková, Lenka (referee)
Human papillomaviruses (HPV) are small, nonenveloped DNA viruses that are abundant in the population. They are sexually transmitted or spread by close contact with mucosa and skin. Papillomaviruses can cause lesions and warts on the skin and mucosa. In addition, high-risk HPV types, especially HPV 16 and 18, are associated with squamous cell carcinomas such as cervical cancer, oropharyngeal cancer and carcinomas of the vulva, anus, penis and vagina. Early detection and the right evaluation of the risk of recurrence are crucial for effective treatment. Cell-free DNA released from cells into body fluids has potential in cancer diagnosis. Cell-free circulating HPV DNA, in the blood of patients with HPV-associated cancers is a promising and highly sensitive biomarker, useful for monitoring treatment efficiency, early detection of the disease and estimation of recurrence risk. Key words: HPV, carcinogenesis, cfDNA, cfHPV DNA, significance of detection, cervical cancer, oropharyngeal cancer
|
|
|
Cell response to genotoxic stress-based anti-cancer therapies
Imrichová, Terezie ; Hodný, Zdeněk (advisor) ; Rossmeislová, Lenka (referee) ; Rotrekl, Vladimír (referee)
The dissertation deals with a cell response to genotoxic stress, specifically to anti-cancer treatments with a genotoxic mechanism of action. In principle, cells can respond to these perturbing stimuli in several ways: in case of severe DNA damage, they usually undergo apoptosis or enter senescence. In case of minor DNA damage, or upon defective checkpoint mechanisms, they may continue the cell cycle, either with successfully repaired DNA or with mutations of various kind. Thanks to selection pressure, the mutations that provide cells with a certain growth advantage under conditions of continuing genotoxic stress, gradually accumulate and render the tumor treatment-resistant. In my thesis, I focus on several aspects of this whole process. First, I participated in a characterization of a radioresistant and anoikis-resistant population of prostate cancer cells. This population was generated by irradiating cells 35 times by 2 Gy, a regime used in clinics. After this treatment, a population of low-adherent cells emerged that demonstrated increased expression of EMT- and stem cell markers. The low-adherent state of these cells was maintained by Snail signaling and their anoikis resistance by ERK1/2 signaling. Interestingly, after a protracted period of time, these cells were able to re-adhere and...
|
|
|
Chicken antibodies as a tool of cytochrome P450 immunodetection
Mácová, Iva ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
Cytochrome P450 is an important enzyme which catalyzes a large amount of reactions of endogenous and exogenous metabolism. There are compounds which increase expression of this enzyme and it leads up to the carcinogen activation and cancer formation. It includes much propagated chemopreventive compounds which are consumed abundantly in dietary supplements. It is therefore important to have the methods for determination of cytochrome P450 induction. One of these methods is the cytochrome P450 immunodetection by Western blotting. The detection of proteins on the membrane is done by the specific antibodies mostly gained from mammals. In this bachelor thesis there is the evidence that the antibodies from hen egg serve as well as the mammalian antibodies. The cytochromes P450 1A1 and 1A2 was detected by these egg antibodies after rat exposure to the model chemopreventive compounds β-naphthoflavone.
|
|
| |
guest ::
