National Repository of Grey Literature 38 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Role of drug transporters in placental transfer of entecavir
Křečková, Veronika ; Červený, Lukáš (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Křečková Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Role of drug transporters in placental transfer of entecavir Entecavir (ETV), an analogue of guanosine, is a highly efficient anti-hepatitis B antiviral drug. It is the first-line therapy for both adults and children. Its use in pregnancy is limited due to a number of factors, including lack of data on placental pharmacokinetics. The placental transition of drugs is frequently controlled by drug transporters. ATP-binding (ABC) transporters, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) or multidrug resistance-associated protein 2 (MRP2) localized in the apical membrane of syncytiotrophoblast and pumping their substrates in the feto-maternal direction belong to most significant determinants of placental pharmacokinetics. Moreover placental transport of nucleoside-derived drugs can be affected by the activity of nucleoside transporters (NTs); equilibrative nucleoside transporters (ENTs) mediate facilitated diffussion, while the concentrative nucleoside transporters (CNTs) control active influx of their substrates. The aim of the diploma thesis was to describe the role of P-gp, BCRP, MRP2 and NTs (ENTs and...
Study on impact of selected protein kinase inhibitors on drug resistance mediated by cytochromes P450
Janoušková, Adéla ; Hofman, Jakub (advisor) ; Novotná, Eva (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Adéla Janoušková Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Study on impact of selected protein kinase inhibitors on drug resistance mediated by cytochromes P450 Pharmacokinetic drug resistance often leads to failure of an anticancer therapy. One of the mechanisms is increased efflux of drugs from tumour cells, whereas some studies suggest that increased drug conversion to an inactive metabolite might be another contributing mechanism. The aim of this work was to define the possible role of CYP3A4 and CYP2C8 enzymes in the phenomenon of pharmacokinetic resistance and to investigate the possibility of its modulation by new targeted drugs. In the first part, we used the MTT proliferation method together with HepG2 cells stably transduced with particular human enzymes and demonstrated significant involvement of CYP3A4 in docetaxel resistance. In the following part, we examined the inhibitory effects of four selected tyrosine kinase inhibitors on the CYP3A4 activity in intact cells using a commercial kit. Cobimetinib and dabrafenib showed significant inhibitory activity, while osimertinib and brivanib did not. In the final part, we demonstrated the ability of the first two...
Study on impact of selected tyrosine kinase inhibitors on multidrug resistance mediated by ABC drug efflux transporters
Sýkorová, Martina ; Hofman, Jakub (advisor) ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Martina Sýkorová Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Study on impact of selected tyrosine kinase inhibitors on multidrug resistance mediated by ABC drug efflux transporters Tyrosine kinases are an important class of enzymes controlling cell proliferation, carcinogenesis, apoptosis and cell differentiation. Deregulation of these enzymes can transform normal cell into a cancerous one. Blocking their function by tyrosine kinase inhibitors (TKi) is considered a promising treatment for various types of cancer. ATP-binding cassette (ABC) transporters form a family of transmembrane proteins that can transport a wide variety of substrates across biological membranes via ATP-dependent drug efflux pumps. They modulate drug pharmacokinetics, but on the other hand, lead to therapy failure due to overexpression in cancer cells. In our previous study, we evaluated inhibition properties of two selected TKi (alectinib, brivanib) in MDCKII cell lines (parent one and those transduced with human ABCB1, ABCC1 and ABCG2). Alectinib significantly inhibited ABCB1, ABCG2 but not ABCC1 transporter. Brivanib showed triple inhibition of all studied transporters. In the present work, we...
Interaction of natural substances with human aldo-keto reductase 7A2 and other important carbonyl reducing enzymes
Homerová, Andrea ; Novotná, Eva (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Andrea Homerová Supervisor: RNDr. Eva Novotná, Ph.D. Title of diploma thesis: Interaction of natural substances with human aldo-keto reductase 7A2 and other important carbonyl reducing enzymes Reduction of carbonyl group is one of the phase I metabolism reactions, which is responsible for production of more polar metabolites, enables conjugation in process of biotransformation, excretion of the molecule and it also causes decrease in reactivity and biological activity of the molecule. Endogenous as well as exogenous compounds undergo this reaction and carbonyl reducing enzymes are the ones which possess this reducing activity. Based on the structure, we can divide the enzymes into several groups: short-chain dehydrogenases/reductases, medium-chain dehydrogenases/reductases, aldo-keto reductases and quinone reductases. Inhibition of carbonyl reducing enzymes appears to be a promising aim of research. It is important to take into consideration that by inhibiting carbonyl reducing enzymes it is possible to reduce production of less active, but more toxic metabolites, for example in anthracycline chemoteraputics daunorubicin and doxorubicin and that can lead to change in therapy of cancer. This study...
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...
The influence of bosutinib, neratinib and ibrutinib inhibition on the activity of selected reductases from AKR and SDR superfamilies
Hudáčová, Lenka ; Wsól, Vladimír (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Lenka Hudáčová Supervisor: Ing. Vladimír Wsól, Ph.D. Title of diploma thesis: The influence of bosutinib, neratinib and ibrutinib inhibition on the activity of selected reductases from AKR and SDR superfamilies Anthracycline antibiotics (ANTs) are antineoplastic drugs. Daunorubicin (DAUN) is used in the treatment of acute leukaemia. Enzymes from aldo-keto reductase (AKR) and short-chain dehydrogenase/reductase (SDR) superfamilies mediate the reduction of DAUN to its C-13 alcohol metabolite daunorubicinol (DAUNOL), which is more cardiotoxic, less antineoplastic and is causing anthracycline resistance. In my diploma thesis, I examined the inhibitory effect of bosutnib, neratinib and imatinib on the activity of enzymes from the SDR and AKR superfamilies. The specific enzyme activity and inhibitory effect were estimated on the base of in vitro enzymatic production of DAUNOL by the ultra-high-performance liquid chromatography (UHPLC) system. MTT assay was used to measure DAUN and ibrutinib cytotoxicity effect on HCT116 cell culture. In vitro enzymatic activities for recombinant enzymes were decreased in order CBR1 > AKR1C3 > AKR1B1 > AKR1A1 > AKR7A2 > AKR1B10 > AKR1C1 > AKR1C2 > AKR1C4 > CBR3. The...
Testing of the cytotoxicity of potential drugs in the cell lines together with the measurement of their passage through the blood brain barrier by the PAMPA method
Šinaĺová, Lucia ; Hofman, Jakub (advisor) ; Jansová, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lucia Šinaľová Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Testing of the cytotoxicity of potential drugs in the cell lines together with the measurement of their passage through the blood brain barrier by the PAMPA method This master thesis focuses on the prediction of tacrine derivatives permeability through blood- brain barrier and their cytotoxicity. We studied tacrine-benzothiazole and tacrine- thiaquinazoline derivates as potential drugs for treatment of Alzheimer's disease. The reason of testing new tacrine derivates was effort to find substances with same effect and lower toxicity, for which was the tacrine discarded from clinical practice. The probable permeability of the studied substances was determined in vitro by the PAMPA method. Based on the permeation coeficient values we have identified that tacrine-benzothiazole derivates A-D (Pe= 8,31- 16,9×10-6 cm/s) and tacrine-thiaquinazoline derivates 1, 3, 4 (Pe= 8,59-14,9×10-6 cm/s) were permeable through blood-brain barrier, tacrine-thiaquinazoline derivate 2 (Pe= 3,79×10-6 cm/s) had uncertain permeability and tacrine-thiaquinazoline derivate 5 (Pe= 2,0×10-6 cm/s) was not permeable. In the pre-clinical evaluation of...
Interactions of selected anticancer drugs of the MAPK/ERK signaling pathway inhibitors group with the ABC drug transporters
Slatinský, Lukáš ; Čečková, Martina (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lukáš Slatinský Supervisor: Assoc. prof. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Interactions of selected anticancer drugs of the MAPK/ERK signaling pathway inhibitors group with the ABC drug transporters ABCB1 (Pgp, P-glycoprotein) and ABCG2 (BCRP, breast cancer resistance protein) are members of a transmembrane efflux ATP dependent transporter family, so called ATP-binding cassettes (ABC). Physiologicaly they are expressed in the cellular membrane and protect body tissues against potentially toxic xenobiotics including drugs. They represent also one of the tumor defense mechanisms when being able to efflux a wide variety of cytotoxic drugs out of the cancer cells leading to treatment failure. BRAF protein plays an important regulatory and signal role in MAPK/ERK pathway affecting cell division, differentiation and secretion. Mutations of BRAF lead to overactivity in MAPK/ERK pathway in many cancer cells and can be therefore targeted by anticancer therapy. Cobimetinib and dabrafenib are relatively new anticancer therapeutics inhibiting the signal pathway mentioned above and they are used in treatment of melanoma carrying the BRAF mutation. The aims of this project were to...
Testing of the cytotoxicity of potential drugs in the cell lines together with the measurement of their passage through the blood brain barrier by the PAMPA method
Šinaĺová, Lucia ; Hofman, Jakub (advisor) ; Jansová, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lucia Šinaľová Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Testing of the cytotoxicity of potential drugs in the cell lines together with the measurement of their passage through the blood brain barrier by the PAMPA method This master thesis focuses on the prediction of tacrine derivatives permeability through blood- brain barrier and their cytotoxicity. We studied tacrine-benzothiazole and tacrine- thiaquinazoline derivates as potential drugs for treatment of Alzheimer's disease. The reason of testing new tacrine derivates was effort to find substances with same effect and lower toxicity, for which was the tacrine discarded from clinical practice. The probable permeability of the studied substances was determined in vitro by the PAMPA method. Based on the permeation coeficient values we have identified that tacrine-benzothiazole derivates A-D (Pe= 8,31- 16,9×10-6 cm/s) and tacrine-thiaquinazoline derivates 1, 3, 4 (Pe= 8,59-14,9×10-6 cm/s) were permeable through blood-brain barrier, tacrine-thiaquinazoline derivate 2 (Pe= 3,79×10-6 cm/s) had uncertain permeability and tacrine-thiaquinazoline derivate 5 (Pe= 2,0×10-6 cm/s) was not permeable. In the pre-clinical evaluation of...
Study of interactions of antiviral drug tenofovir and its prodrug tenofovir disoproxil fumarate with placental nucleoside transporters
Lalinská, Anežka ; Červený, Lukáš (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Anežka Lalinská Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Study of interactions of antiretroviral drug tenofovir and its prodrug tenofovir disoproxil fumarate with placental nucleoside transporters Tenofovir (TFV) in the form of ester prodrug tenofovir disoproxil fumarate (TDF) is an essential part of combination antiretroviral therapy. It is often used in the prevention of perinatal HIV transmission. However, precise mechanism(s) involved in transfer of TFV/TDF from mother to fetus are not described in detail. Since these drugs are nucleoside analogues, there is a possibility that the mechanisms of their transplacental passage might include nucleoside transporters (NTs), either equilibrative or concentrative (ENTs/CNTs). The aim of the diploma thesis was to investigate the role of placental NTs in membrane transfer of TFV and TDF. To address this issue, we performed in vitro accumulation in the BeWo cell line derived from placental choriocarcinoma. By evaluating experiments, we found out that both TFV and TDF might not be substrates of NTs, thus the role of these transporters in TFV/TDF placental pharmacokinetics was not confirmed. Therefore, the drug-drug interactions on NTs...

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14 Hofman, JAkub
5 Hofman, Jan
9 Hofman, Jiří
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