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HSP90 as a target for antitumor therapy
Drápalová, Kateřina ; Zatloukalová, Pavlína (advisor) ; Dibus, Nikol (referee)
Stability and correct tertiary structure of proteins are necessary for maintaining cellular homeostasis. The cell uses molecular chaperones, including Hsp90, to achieve this balance. Hsp90 is an essential protein for healthy and cancer cells. Overexpression of this chaperone is noticeable in many cancers. This thesis summarizes current understandings of the Hsp90 protein and its role in carcinogenesis. Hsp90 became a target of anticancer therapy in the 90s. Inhibition of this chaperone, though successful in many studies, has not yet reached the wanted results in clinical practice. Current failures are mostly caused by high hepatotoxicity and other side effects accompanying the therapy, or the inhibition having insufficient antitumor effects. Nevertheless, the inhibition of the Hsp90 protein represents an interesting approach in antitumor therapy. New inhibitors are constantly being developed and tested in monotherapy or in combination therapy, which demonstrates significantly higher efficacy and, thanks to the synergistic effect, enables the application of a lower concentration of therapeutics.
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Polymer-based therapeutics for immunooncotherapy
Kashmel, Pavel ; Etrych, Tomáš (advisor) ; Bárta, František (referee)
This master thesis describes the synthesis, physico-chemical characterization and preliminary biological testing of water-soluble polymer conjugates of the model drug ZM241385. This drug was first derivatized and then connected to a polymer carrier in order to prepare a system suitable for targeted drug transport to tumor tissues. Improved pharmacokinetic parameters of the prepared polymeric systems carrying ZM241385 should be the basis for increased therapeutic activity of the polymeric nanosystem in tumor immunotherapy. Polymeric precursors were synthesized by controlled RAFT polymerization in order to prepare highly defined carrier systems. In the framework of this master thesis, two derivatives of the selected drug were prepared, differing in the carboxylic acid used and the mode of their binding to the polymeric carrier. For derivatization, 4-(2-oxopropyl)benzoic acid was used, in which case the prepared derivative was bound to the carrier via a hydrazone bond. This bond is pH sensitive and shows high stability at pH 7.4 (corresponds to the pH of the blood stream), and at a slightly acidic pH 5.5 (corresponds to the microenvironment of the tumor, or endosomes of tumor cells), its rapid hydrolysis occurs. For the second derivative, 5-azidopentanoic acid was used. An uncatalysed click reaction...
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The influence of acyclic nucleotide phosphonates PMEG and PMEDAP on p38 kinase signaling in human leukemic cells
Nejedlá, Michaela ; Entlicher, Gustav (advisor) ; Slaninová, Jiřina (referee)
PMEG [9-(2-phosphonomethoxyethyl)guanine] and PMEDAP [9-phosphonomethoxy- ethyl)-2,6-diaminopurine] are acyclic nucleoside phosphonates possessing cytotoxic properties. Antiproliferative effect of PMEG was demonstrated in various tumor cell lines in vitro. PMEG also represents an active component of some experimental prodrugs with enhanced selectivity and efficacy (such as GS-9219). PMEDAP seems to have weaker effect in vitro compared to PMEG, however it exhibited pronounced antitumor effect in SD-rats with spontaneous lymphoma. Therefore it was included in the present study as well. The aim of this study was to describe the interactions of PMEG and PMEDAP with p38 MAP kinase signaling and its relationship to the apoptosis. We investigated the influence of these compounds on the expression of four genes encoding p38 MAPK isoforms and whether this change is translated into the protein. It was found that PMEG up-regulates p38β and γ mRNA in CCRF-CEM cells and p38 β and δ in HL-60 cells. The effect of PMEDAP was less pronounced than that of PMEG. However, total p38 protein level remained unaffected by PMEG and PMEDAP. Activation of p38 MAPK cascade was also measured in the cells exposed to these agents using phospho-specific antibodies. We found that neither PMEG nor PMEDAP activated p38 kinase...
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Molecular mechanisms of apoptosis induction in cancer cells.
Fenclová, Tereza ; Novák, Petr (advisor) ; Milichovský, Jan (referee)
Cancer diseases are now the third leading cause of death (20% of all deaths). It is therefore important to find new ways of getting tumor cells effectively and specifically disposed of and a promising path is targeted therapy. One of the most frequently deregulated protooncogenes in cancer is C-MYC, which makes it suitable as an effective target for treatment. However, the development of such targeted active ingredients is very expensive, so in this thesis we investigate natural substances that have been used for the treatment of cancer in ancient China. We examined the substances shikonin, cnicin and artemisinin. The results show that shikonin induces apoptosis of tumor cells by reducing the expression of C-MYC and activating tumor suppressor kinase MST1. Cnicin reduces the expression of C-MYC as well, but activates MST1 only weakly. Artemisinin, on the other hand, increases expression of C-MYC and doesn't activate MST1, thus operates on inducing apoptosis of tumor cells by a completely different mechanism. (In Czech)
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Study on the role of pharmacokinetic mechanisms of drug resistance in new anticancer drugs with focus on solid tumors
Vagiannis, Dimitrios ; Hofman, Jakub (advisor) ; Souček, Pavel (referee) ; Zendulka, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate Mgr. Dimitrios Vagiannis Supervisor RNDr. Jakub Hofman, Ph.D. Title of Doctoral Thesis Study on the role of pharmacokinetic mechanisms of drug resistance in new anticancer drugs with focus on solid tumors Cancer chemotherapy is an important tool for the cure of cancer. Although the development of new anticancer drugs has been rapidly progressing, the phenomenon of multidrug resistance (MDR) continues to be a key issue leading to therapy failure in oncological patients. MDR is based on pharmacodynamic as well as pharmacokinetic mechanisms. Pharmacokinetic MDR includes drug efflux transporters and biotransformation enzymes that decrease the amount of (active form of) a drug in tumors. While the MDR role of transporters has been well understood, the participation of drug metabolizing enzymes is still unclear. This thesis investigates the role of cytochromes P450 (CYPs) in cytostatic resistance. Furthermore, it focuses on the modulation of pharmacokinetic MDR using pharmacokinetic drug-drug interactions of new targeted antitumor drugs. Finally, it aims to confirm the in vitro findings in ex vivo patient-derived tumor explants. In our latest publication, we demonstrate the significant role of...
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Biodegradable polymer carriers with structure tailored for increased tumor tissue permeability
Hrochová, Michaela ; Etrych, Tomáš (advisor) ; Sedláček, Ondřej (referee)
Cancer diseases are the most common cause of death over the world. One fifth of death is caused by cancer in the Czech Republic. The big problem in the treatment of cancer diseases are side effects of chemotherapy, which make treatment more difficult for patients. The present bachelor thesis is focused on synthesis and characterization of novel polymer carriers. Polymer carriers can target the cytostatic drug to the tumor tissue and minimize side-effect of chemotherapies. This bachelor thesis is focused on synthesis and physical chemistry characterization of new diblock polymer carriers, specifically carries of docetaxel. Successful synthesis of novel water-soluble polymer precursors and conjugates based on N-(2-hydroxypropyl)- methacrylamide is described and discussed in this thesis. The hydrolytic stability of the synthesized diblock systems was studied in 0,3M phosphate buffer at pH 7,4 simulating the bloodstream environment. It has been successfully verified that the synthesized polymer systems are hydrolytically degradable after fulfilling its role of drug carrier and therefore can be finally excreted from the organism. The effect of the type of oxoacid used for modification of the cytostatic on the release rate of the carried cytostatic from the polymeric carriers was thoroughly evaluated and...
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Study on the role of pharmacokinetic mechanisms of drug resistance in new anticancer drugs with focus on solid tumors
Vagiannis, Dimitrios ; Hofman, Jakub (advisor) ; Souček, Pavel (referee) ; Zendulka, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate Mgr. Dimitrios Vagiannis Supervisor RNDr. Jakub Hofman, Ph.D. Title of Doctoral Thesis Study on the role of pharmacokinetic mechanisms of drug resistance in new anticancer drugs with focus on solid tumors Cancer chemotherapy is an important tool for the cure of cancer. Although the development of new anticancer drugs has been rapidly progressing, the phenomenon of multidrug resistance (MDR) continues to be a key issue leading to therapy failure in oncological patients. MDR is based on pharmacodynamic as well as pharmacokinetic mechanisms. Pharmacokinetic MDR includes drug efflux transporters and biotransformation enzymes that decrease the amount of (active form of) a drug in tumors. While the MDR role of transporters has been well understood, the participation of drug metabolizing enzymes is still unclear. This thesis investigates the role of cytochromes P450 (CYPs) in cytostatic resistance. Furthermore, it focuses on the modulation of pharmacokinetic MDR using pharmacokinetic drug-drug interactions of new targeted antitumor drugs. Finally, it aims to confirm the in vitro findings in ex vivo patient-derived tumor explants. In our latest publication, we demonstrate the significant role of...
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The cancer cell proteome and its changes after anti-cancer drug treatment
Tylečková, Jiřina
Cancers represent a group of unprecedented heterogeneous diseases and currently available anti-cancer therapies provide highly variable efficacy with unsatisfactory cure rates. A wide range of proteomic technologies are being used in quest for newer approaches which could significantly contribute to the discovery and development of selective and specific cancer biomarkers for monitoring the disease state and anti-cancer therapy success. Taking into consideration the above aspects, this research was undertaken to study cancer cell proteomes and their changes after anti-cancer treatment with specific focus on: (a) response to conventional anthracycline/anthracenedione drugs with respect to their different clinical efficacy and (b) identification of novel targets for therapy in cancer cells resistant to biological drugs such as inhibitors of (b1) cyclin-dependent kinases and (b2) Aurora kinases. This study identified several interesting key aspects related to the effects of daunorubicin, doxorubicin and mitoxantrone. With the main focus on early time intervals when the influence of apoptosis is minimised, changes common for all three drugs belonging mainly to metabolic and cellular processes were observed. More importantly, significant changes in proteins involved in the generation of precursor...
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Testování inhibitorů GTPas pro studium endocytózy bionanomateriálů
Gráfová, Karolína
Diploma thesis entitled“Testing of GTPase inhibitors for the study of endocytosis of bionanomaterials” is summarizing the importance of bionanotransporters with a special emphasis on apoferritin, characterizes mechanisms of cellular internalization driven by GTPases and also their inhibitors. The following experimental part shows efficacy of apoferritin fluorescence labelling concluding that Cy2 NHS ester would be suitable for following analyses. Afterwards, expression of TfR1 and SCARA5 receptors was deter-mined and toxicity of dynamine inhibitor dynasore was tested. Internalization inhibition of Cy2 labelled apoferritin by dynasore was tested on five cell lines derived from breast tissue (HBL-100, T-47D, MCF-7, MDA-MB-231 and MDA-MB-468). The same cell lines were used for testing of internalization inhibition of Cy2 APO using dynasore, sodium azide or sucrose. The obtained results confirm internalization inhibition by dynasore and also by dynasore in combination with the other two inhibitors. At the same time, complexity of endocytic mechanisms is emphasized, highlighting need for further testing.
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"The cancer cell proteome and its changes after anti-cancer drug treatment".
Tylečková, Jiřina ; Kovářová, Hana (advisor) ; Strnad, Miroslav (referee) ; Petrák, Jiří (referee)
Cancers represent a group of unprecedented heterogeneous diseases and currently available anti-cancer therapies provide highly variable efficacy with unsatisfactory cure rates. A wide range of proteomic technologies are being used in quest for newer approaches which could significantly contribute to the discovery and development of selective and specific cancer biomarkers for monitoring the disease state and anti-cancer therapy success. Taking into consideration the above aspects, this research was undertaken to study cancer cell proteomes and their changes after anti-cancer treatment with specific focus on: (a) response to conventional anthracycline/anthracenedione drugs with respect to their different clinical efficacy and (b) identification of novel targets for therapy in cancer cells resistant to biological drugs such as inhibitors of (b1) cyclin-dependent kinases and (b2) Aurora kinases. This study identified several interesting key aspects related to the effects of daunorubicin, doxorubicin and mitoxantrone. With the main focus on early time intervals when the influence of apoptosis is minimised, changes common for all three drugs belonging mainly to metabolic and cellular processes were observed. More importantly, significant changes in proteins involved in the generation of precursor...
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