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The Role of the Tumour Microenvironment on Melanoma Cell Invasiveness
Jobe, Njainday ; Rösel, Daniel (advisor) ; Kořínek, Vladimír (referee) ; Bušek, Petr (referee)
Cancer cell invasion and metastasis are hallmarks of cancer. It is becoming apparent that the interaction between cancer cells and the surrounding microenvironment are involved in their ability to invade and metastasise. In general, cancer cells can either migrate individually, in an amoeboid or mesenchymal manner, or collectively. The first aim of this thesis was to analyse the role of NG2 in amoeboid to mesenchymal transition (AMT) and Rho/ROCK signalling. We found that NG2 promotes an amoeboid morphology, and increased invasiveness, in a Rho-dependent manner. Secondly, we analysed the role of the major tumour microenvironment (TME) component, cancer-associated fibroblasts (CAFs), on melanoma cell invasiveness. We found the CAF interaction with melanoma cells leads to increased levels of interleukin-6 (IL-6) and IL-8, and this leads to increased invasiveness. Simultaneous blocking of IL-6 and IL-8, using neutralising antibodies, inhibits CAF-dependent invasion. Further analysis of another major component in the melanoma TME, keratinocytes, has highlighted the importance of the tumour cell niche in invasion. Our results indicate that cancer cells have the ability to change morphology, and that the TME plays an important role in melanoma cell invasiveness. Metastatic melanoma treatment has proven...
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Intercellular interactions in malignant melanoma
Nedvědová, Tereza ; Dvořánková, Barbora (advisor) ; Brábek, Jan (referee)
Melanomas are one of the most aggressive types of tumours, with increasing incidence, high mortality and high potential to metastasize to a variety of diverse locations. The aim of this thesis was to study the tumour as a complex structure consisting not only of tumour cells but also of tumour stroma. Stromal cells play a major role in cancer biology. This is well documented for example in squamous cell epithelium tumours of the head and neck. Similar mechanisms can be expected to occur in melanomas. In the first experiment, we simulated the conditions in vivo during the metastatic process and studied the influence of non-adhesive environment both with and without the influence of stromal fibroblasts. The presented data demonstrates a change of tumour cells' phenotype leading to increased plasticity of the melanoma cells in these conditions. It also indicates the crucial role of stromal fibroblasts in interactions with melanoma cells. Cancer cell lines show variability in their behaviour, which is in accordance with well-known melanoma heterogeneity in clinical practice. The previous experiments in our laboratory indicate that cancer associated fibroblasts are able to influence the phenotype of a tumour cell line and this effect is based on a tumour type-unspecific mechanism. In the second part of...
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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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New ferritin nanoparticles for specific targeting of experimental melanoma in mice: in vitro and in vivo tests.
Rajsiglová, Lenka ; Vannucci, Luca Ernesto (advisor) ; Šírová, Milada (referee)
Cancer diseases represent second most frequent cause of death after cardiovascular diseases in Europe. Nowadays used medical treatments like chemotherapy and radiotherapy are nonspecific and cause huge side effects. Various systems to deliver therapy directly inside the tumour microenvironment and reduce side effects are under development. Protein nanoparticles seem to be very promising strategy to achieve that goal. Our group in cooperation with CNR in Rome tested nanoparticles based on heavy chain of human ferritine. These constructs, modified to expose the tumor targeting molecule, were able to be specifically internalised by B16F10 melanoma cells in vitro. They also specifically target and localise at the sites of primary melanoma and lung metastases of different size in mouse in vivo model. These nanoparticles can carry either therapeutic or diagnostic molecules. Thus they represent a suitable candidate for further studies for potential use in clinical praxis as a diagnostic and/or therapeutic agents (theranostics). Powered by TCPDF (www.tcpdf.org)
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DIFFERENTIAL RESISTANCE OF MELANOMA TO VINCA - ALKALOIDS
Rozkydalová, Lucie ; Štaud, František (advisor) ; Čečková, Martina (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and toxicology Student: Lucie Rozkydalová Supervisor of Diploma thesis: Prof. PharmDr. František Štaud, PhD. Specialized supervisor: Pr. Pierre Cuq PharmD. PhD., Laure-Anaïs Vincent Title of diploma thesis: Differential resistance of melanoma to vinca-alkaloids Malignant melanoma (MM) represents the most dangerous and very aggressive skin tumor with fast development of drug resistance which is the main obstacle in successful treatment of MM. According to previous studies (microarray data analysis), KIT gene, which plays key role in melanoma pathophysiology, was chosen as one of the potential causes of failure of treatment by vinca alkaloids (VAs) because of its complete underexpression in melanoma CAL1 resistant cells (CAL1R-VAs) in comparison with parental cells (CAL1-wt). Moreover, KIT also interacted with NF-κB and cyclin D1-2 proteins involved in chemoresistance of melanoma - inside molecular network built using IPA software. Although KIT underexpression in resistant CAL1 R-VAs cell lines were confirmed (qRTPCR), KIT repression using specific siRNA transfection did not show any effect on in vitro sensibility of CAL1-wt cells to VAs. It signifies that KIT is not directly involved in melanoma resistance...
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Function of SWI/SNF chromatin-remodeling complex in tumor initiation and progression of melanoma cells
Ondrušová, Ľubica ; Vachtenheim, Jiří (advisor) ; Goetz, Petr (referee) ; Hejnar, Jiří (referee)
There is an increasing evidence that alterations in chromatin remodeling play an important role in tumorigenesis. The SWI/SNF chromatin remodeling complexes contribute to the regulation of gene expression by altering the local chromatin structure. Depending on the context, they can act as either transcriptional activators or repressors. All SWI/SNF subcomplexes contain one of two ATPase subunits, Brm (Brahma) or Brg1 (Brahma related gene 1), which provide the energy for remodeling. Malignant melanoma is an aggressive cancer and is known for its notorious resistance to conventional anticancer therapies. MITF (microphthalmia-associated transcription factor) plays an essential role in melanoma biology and is placed on the central crossroad in the regulation of melanocyte development, differentation, maintenance of lineage identity, and survival of both normal and malignant melanocytes. Our results show that the active SWI/SNF complex is strictly required for the expression of MITF. This complex is also required for expression of some transcriptional MITF targets. The survival of melanoma cells is absolutely dependent on functional SWI/SNF complex and all subunits of this complex are expressed at high levels in melanoma cell lines. Primarily, Brg1-containing subcomplexes are more important for MITF...
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BRAF mutations in metastatic malignant melanoma.
Hrabcová, Veronika ; Hronek, Miloslav (advisor) ; Vrbacký, Filip (referee)
Bc.Veronika Hrabcová BRAF mutations in metastatic malignant melanoma. Diploma thesis Charles University in Prague, Faculty of Pharmacy in Hradec Králové Healthcare bioanalytics - Specialist in Laboratory Methods Backround: Melanoma is malignant disease with increasing incidency. Treatment of advanced stage of melanoma is still limited. With a progress of knowledge in genetics and tumorigenesis, the incidence of mutated BRAF protein was observed at 50 % of melanomas. In 80-90 % mutated melanomas contain BRAF V600E mutation. The aim of study was to establish a suitable molecular biological method for the diagnosis of mutations in codon V600 BRAF. Methods: Cobas 4800 BRAF V600 mutation test and BRAF StripAssay test were used to analyze DNA. Cobas 4800 BRAF V600 mutation test is based on PCR using TaqMan probes designed for the wild-type and mutant BRAF V600E sequence. BRAF StripAssay test is based on PCR amplification with biotinylated primers and subsequent hybridization of the stripped with allele-specific oligonucleotide probes. Examined DNA samples were derived from 35 patients with advanced malignant melanoma or from archive of laboratory. Results: BRAF V600 mutation was detected in approximately half of the tumors, consistent with the results of other studies. In comparison methods Cobas test...
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The attitude towards prevention and long-term follow-up in patients diagnosed with melanoma
Konkoľová, Radmila ; Provazníková, Hana (advisor) ; Janout, Vladimír (referee) ; Skořepová, Magdalena (referee)
52 7.2 Souhrn v anglickém jazyce Malignant melanoma is the most lethal skin cancer whose incidence has been worldwide increasing. The prognosis of the disease is dependent on many factors - the effected locality, age, form of the tumor and the growth stage at which it was surgically removed. There has been no reliable adjuvant treatment available so far; although cytokins have been recently administered to high-risk patients. The accent is therefore put mainly on the timely detection and the relevant extent of surgical intervention whose degree depends on the stage of the disease. The result of the above mentioned facts is the necessity of an early diagnosis of new cases and permanent follow-up of the patients in whom melanoma has been already confirmed. The patients in the follow-up care are regularly checked, for the rest of their lives, at by the so called melanoma commissions, usually at dermatological clinics. The permanent contact with fact of the possible presence of the disease (information about the diagnosis, repeated follow-ups, waiting for the results of the examination) is stressful for these patients, although they become, to a certain extent, gradually adapted to stress. A good adaptation is however dependent also on the extent of social support, depression, the severity of the disease and...
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