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Studies of intercellular interactions in tumours
Jechová, Alžběta ; Smetana, Karel (advisor) ; Skalníková, Helena (referee) ; Masařík, Michal (referee)
Beside tumor cells themselves, tumors consist of many non-malignantly transformed cellular elements and an extracellular matrix. This so-called tumor microenvironment, or stroma, significantly influences the biological properties of the tumor through intercellular interactions. In this thesis I have focused on the study of tumor-associated fibroblasts in squamous cell carcinomas of the head and neck, malignant melanoma and glioblastoma. The data show the presence of cells with mesenchymal characteristics, present even in the glioblastoma stroma, which could potentially have a positive effect on proliferative activity and invasiveness of glioblastoma cells. In malignant melanoma, the presence of keratinocytes should also be considered, as they are the major cells of the epidermis influencing tumor melanocytes. The conditioned medium from UVB irradiated keratinocytes and non-irradiated fibroblasts stimulates the invasion of malignant melanoma cells. Targeting the tumor stroma may be a new direction in oncological therapy, so we have focused on the influence of synthetic polyamine on the formation of myofibroblasts, which are an active part of the population of tumor-associated fibroblasts. The tested polyamine prevents the formation of myofibroblasts but has no effect on those already formed nor on...
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The Role of Cellular Metabolism in Carcinogenesis. Molecular Pathophysiology of Bladder Cancer Chemoresistance
Kripnerová, Michaela ; Kuncová, Jitka (advisor) ; Nevoral, Jan (referee) ; Chovanec, Miroslav (referee)
Therapeutic resistance of tumours represents an important clinical issue. We can classify the therapeutic tumour resistance in two ways. According to the clinical course, tumours can behave either as primary resistant, i.e. from the very beginning not responsive, or they can display a secondary (also called acquired) resistance, whereby an initial clinical response is lost and the tumour develops into chemo-, radio- or immunoresistant disease. An alternative classification distinguishes cell autonomous resistance mechanisms from resistance that relies on complex interactions within the context of tumour microenvironment. From the research perspective, modelling therapeutic resistance frequently involves experimental treatment of sensitive cancer cells and selection of daughter resistant cell lines. The Ph.D. thesis includes derivation of two unique models of urothelial bladder carcinoma therapeutic resistance. The first model involves newly established urothelial carcinoma cell lines BC44 and BC44DoxoR, which resulted from a prolonged doxorubicin exposure of the mother cell line. The daughter chemoresistant cell line exhibits multidrug resistant phenotype, which extends beyond the selecting drug - doxorubicin - to four additional chemotherapeutic drugs (cisplatin, methotrexate, vinblastine, and...
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Intercellular interactions in skin tumors.
Kučera, Jan ; Smetana, Karel (advisor) ; Masařík, Michal (referee) ; Kovář, Marek (referee)
The dissertation is focused on the study of intercellular interactions in skin tumors. It is based on 5 original publications that cover several topics. We studied the origin of tumor-associated fibroblasts concerning the primary tumor population. We demonstrated using a mouse model that tumor-associated fibroblasts are produced from the host organism and thus did not arise from transformation directly from tumor cells. We also investigated the relationship between tumor-associated fibroblasts and keratinocytes. We have shown that tumor-associated melanoma fibroblasts affect keratinocytes which, under their influence, acquire the features typically observed in migrating cells and cells undergoing epithelial-mesenchymal transition. We studied the interactions between healthy fibroblasts and tumor cells. We have demonstrated that fibroblasts acquired from healthy skin from a patient suffering from melanoma are significantly different from control fibroblasts of healthy donors in the expression profile. Changes in distal fibroblasts support the view of melanoma as a systemic disease. We have further demonstrated that melanoma-associated fibroblasts do not carry a BRAF mutation, in contrast to BRAF positivity of melanoma cells. And therefore, they did not arise from the transition from melanoma. The...
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Role of fibroblasts in wound healing and cancer
Mateu Sanz, Rosana ; Smetana, Karel (advisor) ; Masařík, Michal (referee) ; Mokrý, Jaroslav (referee)
Fibroblasts are stromal cells ubiquitously present in the human body. They often appear in a quiescent state and can become activated in response to tissue remodeling signals. Activated fibroblasts acquire biosynthetic, pro-inflammatory and contractile properties, key functions for wound healing. In addition, the presence of permanently activated fibroblasts is one of the hallmarks of cancer. The purpose of this work is to investigate the differences between newborn and adult fibroblasts and keratinocytes in their implication in scarless wound healing, the origin of cancer associated fibroblasts (CAF)s and the influence of fibroblasts in melanoma invasion. Evidence suggests that wounds heal almost without scar in newborns. To understand the mechanisms that contribute to scarless wound healing we focused on the differences between newborn and adult fibroblasts and keratinocytes, which are cells present in human skin and participating in wound healing process. A comparison of the expression profile between newborn and adult fibroblasts showed differentially regulated genes related to the acute phase of the inflammatory response and ECM organization, traits involved in wound healing. We also found that newborn fibroblast showed higher differentiation potential, exhibited markers of pluripotency and...
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New trends in cell and molecular biology of the head and neck cancer
Fík, Zdeněk ; Chovanec, Martin (advisor) ; Komínek, Pavel (referee) ; Ludvíková, Marie (referee)
Head and neck squamous cell carcinomas are still challenging despite progress in the oncological treatment. Study of the molecular biology allows to deeply characterize tumor properties and to predict the prognosis for affected patients. Nowadays there are many drugs clinically tested in the group of targeted therapy medicine Experimental work comprised both in vitro and in situ assays, being performed thanks to the collaboration between a number of departments of the 1st Faculty of Medicine of the Charles University in Prague, Academy of Sciences of the Czech Republic, Institute of Hematology and Blood Transfusion and Faculty of Veterinary Medicine of the Ludwig-Maxmillian University Munich. Galectin-1 is important inductor of the myofibroblasts/cancer associated fibroblasts. These fibroblasts are regarded as negative prognostic markers thanks to their capability of invasive cancer cells induction. On the other hand, Galectin-9 is not present in the carcinoma and in the case of dysplasia, its expression indicate aberrant features together with aberrant expression of keratin 14 and 19. Except from galectins using as prognostic markers, we focused on the galectins as a therapeutics instruments as well. Presented work with mutant variants of galectin-2 proved their effect on both pharmacodynamics and...
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Glycobiology of the head and neck cancer
Valach, Jaroslav ; Smetana, Karel (advisor) ; Dřízhal, Ivo (referee) ; Říhová, Blanka (referee)
iii Abstract Glycobiology represents a very progressive subject of cell biology. Protein-saccharide interactions play not only supporting and cell organization role, but they also represent medium for information storage and its decoding. Galectins, group of animal lectins (saccharide-binding proteins), which have selective affinity to ß-galactosides, are multifactorial molecules. They participate in cell-cell and cell-matrix interaction, transmembrane signaling, apoptosis, pre- mRNA splicing and are also present in various types of carcinomas. High expression of galectin-1 has been detected in cancer stroma originated from squamous cell epithelium. In the previous study we established that the fibroblasts - myofibroblasts transition, apart from the known TGF- beta, is also induced by galectin-1. We compared relationship between galectin-1 expression, presence of myofibroblasts and gene expression in tissue samples from patients with head and neck squamous cell carcinoma. Cancer stroma with myofibroblasts was rich in galectin-1 expression in comparison with stroma without myofibroblasts. Moreover, we used microarray analysis (ILLUMINA) to compare the whole genome transcriptome from samples with and without presence of galectin-1. High expression of galectin-1 in tissue samples corresponded with expression...
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Glycobiology of the head and neck cancer
Szabo, Pavol ; Smetana, Karel (advisor) ; Říhová, Blanka (referee) ; Brábek, Jan (referee)
Povrch buněk je bohatě pokryt oligosacharidy, které jsou v plazmalemě ukotvené pomocí proteinů a lipidů. Oligosacharidy zprostředkují vzájemnou vazbu mezi buňkami nebo vazbu buněk k složkám extracelulární matrix. Galektiny jsou živočišné lektinů které mají afinitu k oligosacharidům obsahujícím β-galaktózu. Jsou to multifaktoriální proteiny, které se účastňují řady reakcí v organizmu, jako jsou mezibuněčné interakce, interakce buněk s mezibuněčnou hmotou, proliferace i apoptóza a sestřih pre-mRNA. Proteiny po translaci procházejí různými strukturálnimy úpravami, které mají vliv na jejich funkci. Galektin-3 je možný prognostický ukazatel u nádorů vycházejících z vrstevnatých dlaždicových epitelů je fosforylován na N-konci. Prokázali jsme, že tato posttranslační modifikace nemá vliv na jeho vazebnou reaktivitu. Jiný endogenní lektin, galektin-1 je charakteristickou molekulou nádorového stromatu a granulační tkáně hojícího se poranění. Zjistili jsme, že galektin-1 indukuje na TGF-β nezávislý in vitro přechod normálních fibroblastů na myofibroblasty včetně produkce sítě extracelulární matrix bohaté fibronektinem a galektinem-1. Tento poznatek je využitelný v terapii hojení ran a v tkáňovém inženýrství. Dnes je jasné, že nádorové stroma ovlivňuje i biologické vlastnosti nádoru (lokální agresivita,...
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Study of Epithelial Mesenchymal Interactions in Squamous Epithelium Derived Tumors
Kodet, Ondřej ; Lacina, Lukáš (advisor) ; Borovanský, Jan (referee) ; Ehrmann, Jiří (referee)
This thesis is focused on the epithelial mesenchymal interactions in tumors derived from squamous epithelium including tumors arising from minor cell population (melanocytes). This study is also reflecting aspects of epithelial glycobiology resp. the study of endogenous lectins, the galectins, in head and neck squamous carcinomas. Galectins represent, in the current concepts of cell and tumor biology molecules with a remarkable potential. Galectins participate, besides in regulation of pre- and postnatal homeostasis in normal tissues, also in many pathological processes such as autoimmune reactions or malignancies. In this thesis, we demonstrated the presence of galectin-1 and -2 and their glycoligands in interphasic and mitotic nuclei, which may contribute to regulation of the cell cycle. Furthermore, we demonstrated galectin-9 as a sensitive marker of transformation normal to the dysplastic squamous epithelium in head and neck. The epithelial mesenchymal interactions represent mechanisms, which are responsible for dynamic maintenance of the homeostasis of the organism during prenatal development, postnatal growth and during cyclic renewal of certain tissues. These interactions also participate in wound healing. On the other hand they play a crucial role in the process of tumor transformation,...
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Intercellular interactions in skin tumors.
Kučera, Jan ; Smetana, Karel (advisor) ; Masařík, Michal (referee) ; Kovář, Marek (referee)
The dissertation is focused on the study of intercellular interactions in skin tumors. It is based on 5 original publications that cover several topics. We studied the origin of tumor-associated fibroblasts concerning the primary tumor population. We demonstrated using a mouse model that tumor-associated fibroblasts are produced from the host organism and thus did not arise from transformation directly from tumor cells. We also investigated the relationship between tumor-associated fibroblasts and keratinocytes. We have shown that tumor-associated melanoma fibroblasts affect keratinocytes which, under their influence, acquire the features typically observed in migrating cells and cells undergoing epithelial-mesenchymal transition. We studied the interactions between healthy fibroblasts and tumor cells. We have demonstrated that fibroblasts acquired from healthy skin from a patient suffering from melanoma are significantly different from control fibroblasts of healthy donors in the expression profile. Changes in distal fibroblasts support the view of melanoma as a systemic disease. We have further demonstrated that melanoma-associated fibroblasts do not carry a BRAF mutation, in contrast to BRAF positivity of melanoma cells. And therefore, they did not arise from the transition from melanoma. The...
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The Role of Cellular Metabolism in Carcinogenesis. Molecular Pathophysiology of Bladder Cancer Chemoresistance
Kripnerová, Michaela ; Kuncová, Jitka (advisor) ; Nevoral, Jan (referee) ; Chovanec, Miroslav (referee)
Therapeutic resistance of tumours represents an important clinical issue. We can classify the therapeutic tumour resistance in two ways. According to the clinical course, tumours can behave either as primary resistant, i.e. from the very beginning not responsive, or they can display a secondary (also called acquired) resistance, whereby an initial clinical response is lost and the tumour develops into chemo-, radio- or immunoresistant disease. An alternative classification distinguishes cell autonomous resistance mechanisms from resistance that relies on complex interactions within the context of tumour microenvironment. From the research perspective, modelling therapeutic resistance frequently involves experimental treatment of sensitive cancer cells and selection of daughter resistant cell lines. The Ph.D. thesis includes derivation of two unique models of urothelial bladder carcinoma therapeutic resistance. The first model involves newly established urothelial carcinoma cell lines BC44 and BC44DoxoR, which resulted from a prolonged doxorubicin exposure of the mother cell line. The daughter chemoresistant cell line exhibits multidrug resistant phenotype, which extends beyond the selecting drug - doxorubicin - to four additional chemotherapeutic drugs (cisplatin, methotrexate, vinblastine, and...
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