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The detection of hypoxic markers in head and neck tumours
Šťovíčková, Eliška ; Šmahelová, Jana (advisor) ; Rösel, Daniel (referee)
Head and neck cancers (HNSCC) are heterogeneous group of tumours. Risk factors are mainly smoking and alcohol consumption. Some of these tumours are associated with human papillomavirus (HPV) infection, which is a significant positive prognostic factor. These tumours differ from HPV-negative tumours in clinicopathological characteristics, tumour microenvironment and response to treatment. Hypoxia is commonly found in tumors including HNSCC and is a significant prognostic and predictive factor. Elucidating the degree of hypoxia in relation to HPV infection could partly explain the differences in prognosis of these patients and allow more appropriate choice of therapy. Aspartate-β-hydroxylase is also a significant negative prognostic factor in a number of tumours, but its role in HNSCC has not yet been investigated. I focused on the detection of hypoxic markers and aspartate-β-hydroxylase expression in samples from HNSCC patients at the mRNA level by quantitative PCR and at the protein level by multispectral immunohistochemistry. The expression levels of these markers were compared in tumors stratified according to viral etiology and other characteristics such as smoking, localization or tumor stage. HPV infection had the highest impact on the expression of these markers, but the results cannot point to a...
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Role of the PDZ Domain-Binding Motif of the Oncoprotein E6 in the Pathogenesis of High Risk Papillomaviruses
Faflíková, Tereza ; Španielová, Hana (advisor) ; Plocek, Vítězslav (referee)
The infection by high-risk human papillomaviruses is involved in causing cancers. The extreme carboxy terminus of high-risk α-HPV E6 protein contains a PDZ domain-binding motif. The E6 protein of high-risk HPV binds by PDZ domain-binding motif to cellular proteins containing PDZ domain, which participate in the maintenance of the cell polarity, in the stabilization of cell-cell junctions or in the regulation of cellular signaling pathways, e.g. hDlg (human homologue of Discs large protein), hScrib (human homologue of Drosophila tumor suppressor Scribble). Binding of E6 with cellular proteins prevents the induction of apoptosis and influences the enhancement of growth rate of infected cells, degradation of tight-junctions, regulation of cell polarity and vesicular transport. The interaction between E6 and cellular proteins increases the stability of E6 protein and protects E6 from proteasomal degradation. PDZ domain-binding motif of E6 high-risk HPV contributes to the development of malignant tumors.
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Analysis of miRNAs in HPV-associated carcinomas
Pagáčová, Lucie ; Tachezy, Ruth (advisor) ; Vopálenský, Václav (referee)
Papillomaviruses are small DNA viruses that are associated with the induction of epithelial tumors. HPV is an important infectious agent causing almost 100 % of cervical tumors but it can also cause tumors in other anogenital and head and neck locations in both men and women. Active HPV infection induces changes in miRNA expression that contribute to the tumor formation and progression. It is already known that papillomaviruses do not encode their own viral miRNAs but they affect the expression of cellular miRNAs. In my thesis I have in selected epithelial tumors (vulva, cervix, anus and tonsils) determined their etiology and analyzed the presence of miRNAs in tissues by next generation sequencing. From these data I determined the expression profiles of deregulated miRNAs in tumors relation to healthy tissues of corresponding location. Even though, sufficient number of samples was analyzed, it was not possible to detect HPV-core miRNA common to all analyzed HPV-induced tumors due to the absence of statistically relevant differentially expressed miRNAs in HPV positive vulvar tumors. Among the tumors of the other sites I found an overlap in three miRNAs. One of these miRNAs (miR-139-5p) and another one (miR-9-5p) which I have selected based on the study of other published data, were used for...
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Vesicular trafficking from acidic compartments to the endoplasmic reticulum
Polidarová, Markéta ; Forstová, Jitka (advisor) ; Plocek, Vítězslav (referee)
The cell uses retrograde transport from endosomes to Golgi apparatus and further to the endoplasmic reticulum to recycle its receptors and other proteins. There are several pathways starting on different types of endosomes aimed to the trans-Golgi network and from it further to the endoplasmic reticulum. From the early and maturing endosomes the proteins are transported using the retromer complex. Rab9 GTPase is essential for transport from the late endosomes. Rab6 and Rab11 play major role in the transport form the recycling endosomes. There are two pathways going through the Golgi apparatus. The first one is mediated by COPI vesicles which are regulated by Arf1 GTPase and the pathway is sensitive to brefeldin A. The second pathway is regulated by Rab6 GTPase. Except for endogenous proteins the retrograde transport is used by protein toxins and small unenveloped DNA viruses as well. Rab6 pathway from the recycling endosomes and through the Golgi apparatus is characteristic for Shiga toxin. The retrograde transport of ricin starts on the early endosomes and is less clear. Scientists only started uncovering the transport of small unenveloped DNA viruses.
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Analysis of miRNAs in HPV-associated carcinomas
Pagáčová, Lucie ; Tachezy, Ruth (advisor) ; Vopálenský, Václav (referee)
Papillomaviruses are small DNA viruses that are associated with the induction of epithelial tumors. HPV is an important infectious agent causing almost 100 % of cervical tumors but it can also cause tumors in other anogenital and head and neck locations in both men and women. Active HPV infection induces changes in miRNA expression that contribute to the tumor formation and progression. It is already known that papillomaviruses do not encode their own viral miRNAs but they affect the expression of cellular miRNAs. In my thesis I have in selected epithelial tumors (vulva, cervix, anus and tonsils) determined their etiology and analyzed the presence of miRNAs in tissues by next generation sequencing. From these data I determined the expression profiles of deregulated miRNAs in tumors relation to healthy tissues of corresponding location. Even though, sufficient number of samples was analyzed, it was not possible to detect HPV-core miRNA common to all analyzed HPV-induced tumors due to the absence of statistically relevant differentially expressed miRNAs in HPV positive vulvar tumors. Among the tumors of the other sites I found an overlap in three miRNAs. One of these miRNAs (miR-139-5p) and another one (miR-9-5p) which I have selected based on the study of other published data, were used for...
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Biological treatment and its influence on the course of latent viral infections in patients with psoriasis
Laurin, Josef ; Šmahelová, Jana (advisor) ; Janovec, Václav (referee)
There are more than 80 identified autoimmune diseases. One of the most prevalent ones is psoriasis. Its prevalence is around 2-5 % worldwide. The treatment of this inflammatory skin disease can be divided as follows: in cases of low severity, topical therapies are used for local treatment and in the cases of insufficient effect, stronger therapies are used. Phototherapy is used for moderate severity, and systemic therapy is used in moderate to severe disease. Systemic agents include cytostatic methotrexate, immunosuppressant cyclosporin, or retinoids (vitamin A analogues). However, even systemic therapies may not yield the desired effects or may have adverse effects on the overall condition of the patient. In those cases, biological therapy comes to use. Biological therapy is usually conducted using antibodies and fusion proteins, which are made using recombinant technologies. Tumour necrosis factor α (TNF-α) and interleukin 12, 17 and 23 (IL-12, IL-17 and IL-23) inhibitors are the most commonly used in the treatment of psoriasis. During the inhibition of the immune system, it has been confirmed that a reactivation of viral infections can occur. These reactivations may subsequently lead to the development of various diseases caused by latent viral infections.
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Vesicular trafficking from acidic compartments to the endoplasmic reticulum
Polidarová, Markéta ; Forstová, Jitka (advisor) ; Plocek, Vítězslav (referee)
The cell uses retrograde transport from endosomes to Golgi apparatus and further to the endoplasmic reticulum to recycle its receptors and other proteins. There are several pathways starting on different types of endosomes aimed to the trans-Golgi network and from it further to the endoplasmic reticulum. From the early and maturing endosomes the proteins are transported using the retromer complex. Rab9 GTPase is essential for transport from the late endosomes. Rab6 and Rab11 play major role in the transport form the recycling endosomes. There are two pathways going through the Golgi apparatus. The first one is mediated by COPI vesicles which are regulated by Arf1 GTPase and the pathway is sensitive to brefeldin A. The second pathway is regulated by Rab6 GTPase. Except for endogenous proteins the retrograde transport is used by protein toxins and small unenveloped DNA viruses as well. Rab6 pathway from the recycling endosomes and through the Golgi apparatus is characteristic for Shiga toxin. The retrograde transport of ricin starts on the early endosomes and is less clear. Scientists only started uncovering the transport of small unenveloped DNA viruses.
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Role of the PDZ Domain-Binding Motif of the Oncoprotein E6 in the Pathogenesis of High Risk Papillomaviruses
Faflíková, Tereza ; Španielová, Hana (advisor) ; Plocek, Vítězslav (referee)
The infection by high-risk human papillomaviruses is involved in causing cancers. The extreme carboxy terminus of high-risk α-HPV E6 protein contains a PDZ domain-binding motif. The E6 protein of high-risk HPV binds by PDZ domain-binding motif to cellular proteins containing PDZ domain, which participate in the maintenance of the cell polarity, in the stabilization of cell-cell junctions or in the regulation of cellular signaling pathways, e.g. hDlg (human homologue of Discs large protein), hScrib (human homologue of Drosophila tumor suppressor Scribble). Binding of E6 with cellular proteins prevents the induction of apoptosis and influences the enhancement of growth rate of infected cells, degradation of tight-junctions, regulation of cell polarity and vesicular transport. The interaction between E6 and cellular proteins increases the stability of E6 protein and protects E6 from proteasomal degradation. PDZ domain-binding motif of E6 high-risk HPV contributes to the development of malignant tumors.
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