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MRP transporters in the placenta
Dvořáková, Marie ; Čečková, Martina (advisor) ; Pávek, Petr (referee)
The MRP mebrane proteins, which belong to the ABC transporter family, comprise currently 9 members. The MRP transport proteins are expressed in various tissues of the organism, including placenta. The major physiological role of the multidrug transporters is the transport of many endogenous and exogenous compounds, including drugs, across the cell membrane. This thesis summarizes up to date information concerning expression and function MRP transporters in placenta a and in other tisssues in organism. Only five MRP transporters have been detected in placenta, namely MRP1, MRP2, MRP3, MRP5 a MRP8. Expression of all this proteins in placenta changes with progress of the pregnancy. MRP transporters help to protect fetus from potentially toxic substances, on the other hand some of them can facilitate the passage of substances across placenta. Some MRPs possess specific physiological functions in placenta. For example, MRP1 influences apoptosis, MRP5 participates in NO-dependent vasodilatation in fetal vessels.
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The role of ABC transporter in clinical practise
Tornová, Petra ; Pávek, Petr (advisor) ; Čečková, Martina (referee)
The role of ABC transporters in clinical practice ATP-binding cassette (ABC) transporters are a family of transporter proteins that contribute to drug resistance via ATP-dependent drug efflux pumps. There are seven subfamilies classified as ABC transporters (ABCA through ABCG) that are expressed in both normal and malignant cells. They are involved in the transport of many substances, including the excretion of toxins from the liver, kidneys, and gastrointestinal tract, and they limit permeation of toxins to vital structures, such as the brain, placenta, and testis. The best-characterized transporter protein is MDR1/P-glycoprotein, and a number of clinical investigations have suggested that its intrinsic or acquired overexpression resulted in a poor clinical outcome of chemotherapy. Conventional cancer chemotherapy is seriously limited by the multidrug resistance (MDR) commonly exhibited by tumour cells. One mechanism by which a living cell can achieve multiple resistances is via the active efflux of a broad range of anticancer drugs through the cellular membrane. Various types of compounds and techniques for the reversal of ABC transporters mediated MDR have been developed, and efforts have concentrated on the inhibition of function and suppression of expression. Increased drug accumulation and...
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The study of interaction of platinum cytostatics with BCRP drug transporter using MTT cytotoxicity test
Horká, Markéta ; Čečková, Martina (advisor) ; Štaud, František (referee)
AAbbssttrraacctt The resistance of oncological diseases to cytostatic treatment is considered as one of the most serious problems of cancer treatment. One of the mechanisms by which cancers develop resistance is the overexpression of efflux transport proteins that limit intracellular concentrations of substrate agents. This work is focused on study of the interaction between clinically used platinum cytostatics (cisplatinum, carboplatinum and oxaliplatinum) and the efflux transport protein - BCRP. The experiments were made on MDKCII (parental cell line) and MDCKII-BCRP (cells were transfected by the gene of BCRP) cell lines. The results of the experiment with oxaliplatinum did not confirm any effect of BCRP on viability of BCRP transfected cells. Cisplatinum and carboplatinum tests provided evidence that BCRP transporter plays an important role in resistance development. The cells that were transfected by the gene of BCRP showed remarkably enhanced viability than parental MDCKII cells. However, the inhibition of BCRP transporter by specific inhibitor fumitremorgin C did not affect the viability of MDCK-BCRP cells. Such results suggest that the resistance of transfected cells was developed by other mechanism. Enhanced resistance could be caused by EGFP which is used as a reporting protein in preparation of...
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Pokračování studie Kuopio 75+: Prevalence ortostatické hypotenze
Henzlová, Veronika ; Čečková, Martina (advisor) ; Štaud, František (referee)
Kuopio study 75+: The prevalence of orthostatic hypotension Veronika Henzlová Abstract This master thesis deals with the prevalence of orthostatic hypotension in home-dwelling elderly. It is a part of the follow-up study Kuopio 75+ conducted in 2003 in Finland. SPSS 14 was used for statistic purpose. The prevalence of orthostatic hypotension was stated to be 23,7%. No difference in prevalence was found in genders, age groups and systolic blood pressure groups.
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Mechanizmy vzniku rezistence vůči platinovým cytostatikům
Bouška, Petr ; Štaud, František (referee) ; Čečková, Martina (advisor)
1. Abstract Although the first platinum drug cisplatin was initially described in 1845, its biological activity was discovered more than 100 years later. Since then are cisplatin and its clinically used analogues carboplatin and oxaliplatin in widespread use for the treatment of variety of human cancers, including ovarian, cervical, head and neck tumors, non-small cell lung, breast, colon, gastric and renal cell carcinoma, sarcoma and relapsed lymphoma. However, the treatment is often accompanied by severe side effects of which nephrotoxicity, peripheral neurotoxicity and myelosuppression are the most serious. Another important obstacle in their clinical use is drug resistance. This thesis evaluates possible mechanisms of the development of platinum drugs resistance. There is a variety of them and they include (i) diminished accumulation of platinum drugs affected by influx transporters (Aquaporin 9, CTR1, OCT1, OCT2) and by efflux transporters (ATP7A, ATP7B,ABCG2); (ii) increased detoxification of drug by thiols glutathione and metallothionein; (iii) improved repair of nuclear lesions affected by NER, MMR, Homologous recombination, and enhanced tolerance to nuclear lesions caused by Replicative bypass, inhibition of pro-apoptic factors (including caspase-3, -8, Fas and other), or by overexpression of...
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Study of the Effect of EGFP on Cytotoxicity of Platinum-based Drugs
Musilová, Markéta ; Štaud, František (referee) ; Čečková, Martina (advisor)
Charles University in Prague Faculty of Pharmacy in Hradci Králové Department of pharmacology and toxicology Mgr. Markéta Musilová Master thesis Study of the effect of EGFP on cytotoxicity of platinum-based drugs Abstract The aim of the present study is to investigate possible impact of EGFP on the resistance of cancer cells to platinum-based drugs (cisplatin, carboplatin and oxaliplatin). The work follows on our previous study with BCRP efflux transporter, which suggested that higher resistance of cancer cells to platinum-based drugs is caused rather by the presence of EGFP than by the efflux transporter. To confirm this hypothesis series of cytotoxic MTT tests were performed on human Hep2 parent cell line and Hep2-EGFP cell line transfected for the expression of EGFP. Our results demonstrated higher tolerance of transfected Hep2-EGFP cells to platinum-based drugs compared with the parent Hep2 cell lines. Based on the obtained results we conclude that EGFP interferes with the toxicity of platinum-based drugs, which can cause misinterpretation of results obtained in the cytotoxicity studies.
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Nové přístupy léčby prsního nádoru
Ahmadimoghaddam, Davoud ; Štaud, František (advisor) ; Čečková, Martina (referee)
Breast cancer is a malignant tumor that originates in the cells of the breast both in women and men. It is the second leading cause of cancer death in women today. Risk factors causing breast cancer in humans comprise, among others, prolonged exposure to estrogen, ionizing radiation, genetic predisposition (BRCA1, BRCA2, others), sedentary lifestyle, high-fat diet, alcohol, and tobacco smoking. Classical treatment strategies include chemotherapy, surgery and radiotherapy. The aim of this diploma thesis was to review recent developments in breast cancer treatment, such as endocrine therapy, molecular targeting therapy as well as breast cancer stem cells.
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Principy transportu léčiv přes placentu: nové aspekty pro farmakoterapii v těhotenství
Schönwälderová, Denisa ; Čečková, Martina (advisor) ; Pávek, Petr (referee)
7.SUMMARY After thalidomide-induced birth defects affair, the view of uterus as pharmacologically unconquerable site dramatically changed. Subsequently it was accepted that any chemical substance permeates across the placenta. As there was a continuing need for many mothers to continue to receive medications for chronic disease states, extensive research was launched to gain an appropriate rationale. Progressive investigation of placental barrier compounds allowed the emergence of in vitro and in vivo models, which enabled particularly drug transport studies. Syncytiotrophoblast plays an important role as a rate-limiting component of the barrier. Detailed understanding of pharmacokinetic changes that occur during gestation offered a rationale for pharmacotherapy in pregnancy (large charged molecule, excessive protein-binding, short elimination half-life, volume of distribution, fetal-maternal serum pH gradient). The mechanism of passive diffusion is most important way of drug transport. Perfusion studies clarified the crucial role of active efflux transporters, members of ABC protein family, namely P-glycoprotein, multidrug resistence-associated proteins a ABCG2. As P- gp was first to be discovered, is the most studied until now. Its substrates and inhibitors are well defined and their interactions are...
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Monitoring of ABC-transporter expression at the transcription level
Kalmanová, Milada ; Štaud, František (advisor) ; Čečková, Martina (referee)
Human ABC (ATP-binding cassette) family of active transporters contains about 50 functionally diverse transmembrane proteins. They utilize energy from the hydrolysis of ATP and transport a variety of endogenous and exogenous compounds across the membranes against a concentration gradient. ABC transporters play important role in absorption, distribution and excretion of drugs. Some are able to confer multidrug resistance in cancer cells. Nowadays, to observe expression of ABC transporters on transcription level, it is possible to use several methods as Northern blotting, RNase protection assay, real-time RTPCR and microarray analysis. This thesis summarizes up to date information about quantification of ABC drug transporters. It was found that ABC transporters are expressed in the liver, kidney, gastrointestinal tract, blood-brain barrier, placenta and other tissues.
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