National Repository of Grey Literature 118 records found  beginprevious45 - 54nextend  jump to record: Search took 0.01 seconds. 
Participation of Selected Carbonyl Reductases in Deactivation of Anticancer Drugs
Odiana, Romana ; Wsól, Vladimír (advisor) ; Szotáková, Barbora (referee) ; Heidingsfeld, Olga (referee)
Reduction is the reverse of oxidation and therefore it can involve loss of oxygen atom or the addition of two hydrogen atoms. The reduction of carbonyl groups in xenobiotics was the main topic of this thesis. We tried to identify and characterize human carbonyl reductases responsible for anticancer drugs deactivation. When cancer is among the most common death causes in the developed world, it is necessary to look for new and efficient ways of its treatment. Inhibition of enzymes, which may contribute to disease development or relapses and/or treatment efficacy decrease by drug inactivation, could be a possible way of treatment improvement and might also lead to decrease of drug doses and side effects of cytostatics. In the first part of our project, we focused on a soluble cytosolic reductase AKR1C3. This enzyme is involved in sex hormone metabolism and might play an important role in breast and prostate cancer development. We tested its ability to metabolize anticancer drugs by its incubation with oracin and doxorubicin with subsequent metabolite determination with use of HPLC. Our experiment proved that it can deactivate these two drugs with Km 355 μM for doxorubicin and 110 μM for oracin, respectively. AKR1C3 can therefore influence the anticancer therapy, expecially when overexpressed. The...
Phase II biotransformation of NSAID flobufen
Babú, Yogeeta ; Wsól, Vladimír (advisor) ; Nobilis, Milan (referee) ; Kuchař, Miroslav (referee)
Xenobiotic chemicals are chemicals foreign to life that are usually derived synthetically or from an abiotic process. The synthetic xenobiotic chemicals are often of enormous value to human society and are usually the majority of the chemicals in such important groups of substances as petrochemicals, pesticides, plastics and pharmaceuticals, where the term drug is usually applied when referring to xenobiotics. Biotransformation is a major mechanism for drug elimination, as they undergo biotransformation after they enter the body. Biotransformation, which almost always produces metabolites that are more polar than the parent compound, usually terminates the pharmacologic action of the parent drug and, via excretion, increases removal of the drug from the body. However, other consequences are possible, including similar or different pharmacologic activity, or toxicological activity. The routes by which drugs may be biotransformed are many and varied and include oxidation, reduction, hydrolysis and conjugation reactions, among others. It is important that these pathways are understood, as the route of metabolism of a drug can determine its ultimate pharmacological or toxicological activity. Drug biotransformation is divided into two phases: Phase I, or functionalisation reactions and Phase II, or conjugative...
Regulation of Human Carbonyl Reductase 3 (CBR3) Expression
Malátková, Petra ; Wsól, Vladimír (advisor) ; Pávek, Petr (referee) ; Machala, Miroslav (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate Mgr. Petra Malátková Supervisor Prof. Ing. Vladimír Wsól, Ph.D. Title of Doctoral Thesis Regulation of Human Carbonyl Reductase 3 (CBR3) Expression The regulation of human carbonyl reductase 3 (CBR3) expression has been complete mystery until recently and is still not well understood. Because the transcriptional regulation of a gene is closely related to the function of encoded protein, the elucidation of the regulation of CBR3 might help to understand its physiological role which has not been elucidated up to the present. The promoter of CBR3 has been described in 2009. The CBR3 promoter contains several putative binding sites for various transcription factors. In 2010, we have shown that CBR3 is regulated via the Nrf2/ARE signaling pathway. This was the first study about the transcriptional regulation of CBR3. The involvement of Nrf2 in the regulation of CBR3 has been recently confirmed by another research group. The functional antioxidant response element (ARE) is located at 2698 bp upstream of the translation initiation codon of CBR3 (−2698ARE). However, the analysis of CBR3 promoter encompassing 2500 bp indicated the presence of cis regulatory upstream element in sequence between...
Effect of evobrutinib on cancer cell resistance to daunorubicin caused by carbonyl reducing enzymes
Zenkerová, Katharina ; Wsól, Vladimír (advisor) ; Macháček, Miloslav (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Mgr. Katharina Zenkerová Supervisor: Prof. Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: Effect of evobrutinib on cancer cell resistance to daunorubicin caused by carbonyl reducing enzymes Anthracyclines (ANT) have been among the first line treatments for many types of cancer, including acute myeloid leukemia, for decades. These chemotherapeutic agents target topoisomerase II, interfere with DNA and RNA synthesis by intercalation, and induce apoptosis by forming reactive oxygen species. As with many other chemotherapeutics, administration of ANT is associated with a range of adverse effects, particularly cardiotoxicity and resistance. The culprit responsible for this cardiotoxicity is the hydroxy metabolite of ANT, formed by reduction of the carbonyl group at position 13. This metabolite is also considerably less cytotoxic; cancer cells excessively metabolize ANT, thus developing resistance to their effects. Enzymes involved in the ANT reductions are NADPH dependant carbonyl reducing enzymes, primarily from aldo-keto reductase and short-chain dehydrogenase/reductase superfamilies. These enzymes are frequently over-expressed in cancer cells and they might be an attractive target of novel...
The effect of olaparib on tumor cell resistance to daunorubicin due to carbonyl reducing enzymes.
Lekešová, Alžběta ; Wsól, Vladimír (advisor) ; Macháček, Miloslav (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Alžběta Lekešová Supervisor: prof. Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: The effect of olaparib on tumor cell resistance to daunorubicin due to carbonyl reducing enzymes Daunorubicin (DAUN) belongs to the group of anthracycline antibiotics, belonging to the group of cytostatics used in a wide range of different carcinomas. However, even with this group of drugs, the resistance to chemotherapy, followed by treatment failure is becoming more and more common. This problem of resistance is often dealt with by combination therapy, which uses the addition of drugs that affect the cytostatic by different mechanisms. One possibility is to keep the cytostatic in tumor cells in their active form for as long as possible. This may be affected by the blockade of efflux transporters or inhibition of enzymes responsible for the inactivation of cytostatics. The possible inhibition of enzymes by the low molecular weight drug olaparib (OLA) was studied in this diploma thesis. OLA is a drug with a cytostatic effect on its own and has been used in certain cancer therapies for several years. We tested its inhibitory potential to selected carbonyl reducing enzymes, which are involved in the metabolism of...
Inhibitory effect of tepotinib, entrectinib, and sapanisertib on an activity of selected reductases from AKR superfamily.
Krtilová, Kamila ; Wsól, Vladimír (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Kamila Krtilová Supervisor: prof. Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: Inhibitory effect of tepotinib, entrectinib, and sapanisertib on an activity of selected reductases from AKR superfamily. The lung carcinoma has an increasing trend in the Czech Republic. These findings correspond to the fact that lung carcinoma is the most common type of cancer worldwide. Carbonyl reducing enzymes occur in different types of tissues, and they are responsible for the development of inflammation, cancer, and cancer resistance. These NADPH-dependent oxidoreductase cause the reduction of carbonyl groups to alcohol compound and decrease the toxicity of drug for tumor cells. Last but not least, these enzymes are responsible for tumor cell proliferation, differentiation, and increased tumoral aggressivity. This work aimed to study the inhibition effect of chosen cyclin-dependent kinase inhibitors (CDKi) on the activity of Aldo-keto reductases. Besides inhibition of CDK, the ability to inhibit efflux transporters and carbonyl reducing enzymes was proved at CDK inhibitors. The inhibition effect of tepotinib, entrectinib and sapanisertib was determined by UHPLC analysis. The most significant inhibition...
The influence of belinostat inhibition on the activity of selected reductases from AKR and SDR superfamilies.
Slámová, Adéla ; Wsól, Vladimír (advisor) ; Macháček, Miloslav (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Adéla Slámová Supervisor: prof. Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: The influence of belinostat inhibition on the activity of selected reductases from AKR and SDR superfamilies Anthracycline antibiotics (ANTs) are important antineoplastic agents. One of them, daunorubicin (DAUN), is used for the treatment of acute leukaemia and other malignancies in children and adults. Factors limiting its clinical use include mainly resistance and cardiotoxicity. Enzymes from aldo-keto reductase (AKR) and short-chain dehydrogenase/reductase (SDR) superfamilies mediated the reduction of DAUN to its C-13 alcohol metabolite daunorubicinol (DAUNOL). The metabolite is more cardiotoxic, less antineoplastic, and is causing anthracycline resistance. This diploma thesis aimed to examine the inhibitory effect of belinostat on the activity of AKR1A1, 1B1, 1B10, 1C3, and CBR1. The specific enzyme activity and inhibitory potential were estimated in vitro using recombinant enzymes, and the enzymatic production of DAUNOL was evaluated by the liquid chromatography (UHPLC) system. The inhibition was decreased in order AKR1C3  AKR1B10  AKR1A1  AKR1B1  CBR1. The most inhibited enzyme, AKR1C3, expressed 50,7%...
The influence of enasidenib, glasdegib, and quizartinib inhibition on the activity of selected reductases from AKR and SDR superfamilies.
Pěčková, Alexandra ; Wsól, Vladimír (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Alexandra Pěčková Supervisor: prof. Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: The influence of enasidenib, quizartinib and glasdegib inhibition on the activity of selected reductases from AKR and SDR superfamilies Acute myeloid leukemia is the most common cancerous disease among the adult population. The treatment is dependent on many factors, where the effectiveness of anthracycline antibiotic cytostatic treatment plays a significant role. Therapy is often complicated by resistance to anthracyclines. This resistance can be caused by carbonyl reducing enzymes which also may aid in tumor growth. Carbonyl reducing enzymes are NAD(P)H-dependent oxidoreductases, reducing anthracyclines to respective alcohols, which not only have lower toxicity towards the cancerous cells, but can also damage the cardiac tissue. These enzymes also aid in the differentiation and proliferation of cancerous cells and increase the tumor aggressiveness. The topic of this thesis was to study the inhibitors of carbonyl-reducing enzymes from aldo-keto reductase and short chain dehydrogenase/reductase superfamilies, reducing daunorubicin to less effective metabolite daunorubicinol. The three selected inhibitors were:...
Inhibitory effect of tepotinib, entrectinib, and sapanisertib on an activity of selected reductases from AKR superfamily.
Krtilová, Kamila ; Wsól, Vladimír (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Kamila Krtilová Supervisor: prof. Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: Inhibitory effect of tepotinib, entrectinib, and sapanisertib on an activity of selected reductases from AKR superfamily. The lung carcinoma has an increasing trend in the Czech Republic. These findings correspond to the fact that lung carcinoma is the most common type of cancer worldwide. Carbonyl reducing enzymes occur in different types of tissues, and they are responsible for the development of inflammation, cancer, and cancer resistance. These NADPH-dependent oxidoreductase cause the reduction of carbonyl groups to alcohol compound and decrease the toxicity of drug for tumor cells. Last but not least, these enzymes are responsible for tumor cell proliferation, differentiation, and increased tumoral aggressivity. This work aimed to study the inhibition effect of chosen cyclin-dependent kinase inhibitors (CDKi) on the activity of Aldo-keto reductases. Besides inhibition of CDK, the ability to inhibit efflux transporters and carbonyl reducing enzymes was proved at CDK inhibitors. The inhibition effect of tepotinib, entrectinib and sapanisertib was determined by UHPLC analysis. The most significant inhibition...
The influence of midostaurin, vistusertib and talazoparib inhibition on the activity of selected reductases from AKR and SDR superfamilies
Milan, Jaroslav ; Wsól, Vladimír (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical sciences Candidate: Bc. Jaroslav Milan Supervisor: prof. Ing. Vladimír Wsól, PhD. Consultant: RNDr. Eva Novotná, PhD. Title of diploma thesis: The influence of midostaurin, vistusertib and talazoparib inhibition on the activity of selected reductases from AKR and SDR superfamilies. Key words: reductase, AKR, inhibitors, midostaurin, vistusertib, talazoparib, anthracyclines, KG1a Multi drug resistance is for a lot of years still a big problem in therapy of cancer. Anthracycline antibiotics are highly efficient for treating cancers but multi drug resistance and severe side effects sometimes restrain the use of them and lead therapy to fail. One of the worst adverse effect is a cardiotoxicity. By older studies, the mechanism of a cardiotoxicity was because of formation of reactive oxygen species (ROS). Many times, the negative effects of ROS on cardiac muscle cells was confirmed but nowadays the evidence opens some other and more complex mechanisms of its damage. The main point of this work was examination of enzymes which metabolize anthracyclines, mainly daunorubicin. Metabolites which are formed are less potent than parent drug and they have bigger toxicity. This can have an impact on therapy and can cause a...

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