Dabrafenib is a BRAF inhibitor used in combination treatment of malignant melanoma and non-small cell lung carcinoma. In this study, we aimed to characterize its interactions with cytochrome P450 (CYP) isoenzymes and ATP-binding cassette (ABC) efflux transporters that have critical impact on the pharmacokinetics of drugs and play a role in drug resistance development. Using accumulation assays, we showed that dabrafenib inhibited ABCG2 and, less potently, ABCB1 transporter. We also confirmed dabrafenib as a CYP2C8, CYP2C9, CYP3A4, and CYP3A5 inhibitor. Importantly, inhibition of ABCG2 and CYP3A4 by dabrafenib led to the potentiation of cytotoxic effects of mitoxantrone and docetaxel toward respective resistant cell lines in drug combination studies. On the contrary, the synergistic effect was not consistently observed in ABCB1-expressing models. We further demonstrated that mRNA levels of ABCB1, ABCG2, ABCC1, and CYP3A4 were increased after 24 h and 48 h exposure to dabrafenib. Overall, our data confirm dabrafenib as a drug frequently and potently interacting with ABC transporters and CYP isoenzymes. This feature should be addressed with caution when administering dabrafenib to patients with polypharmacy but also could be utilized advantageously when designing new dabrafenib-containing drug combinations to improve the therapeutic outcome in drug-resistant cancer.

• MeSH
• ABC transportér z rodiny G, člen 2 antagonisté a inhibitory   genetika   metabolismus   MeSH
• antitumorózní látky aplikace a dávkování   farmakologie   MeSH
• buňky MDCK MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• daunomycin aplikace a dávkování   farmakologie   MeSH
• imidazoly aplikace a dávkování   farmakokinetika   MeSH
• inhibitory cytochromu P450 aplikace a dávkování   farmakologie   MeSH
• kombinovaná farmakoterapie MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mitoxantron aplikace a dávkování   farmakologie   MeSH
• nádorové buněčné linie MeSH
• oximy aplikace a dávkování   farmakokinetika   MeSH
• P-glykoprotein antagonisté a inhibitory   genetika   metabolismus   MeSH
• psi MeSH
• regulace genové exprese účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Achieving fast immunosuppression blood exposure after kidney transplantation is key to abrogating both preformed and de novo anti-donor humoral and cellular alloresponses. However, while tacrolimus (TAC) is the cornerstone immunosuppressant inhibiting adaptive alloimmunity, its blood exposure is directly impacted by different single-nucleotide polymorphisms (SNPs) in CYP3A TAC-metabolizing enzymes. Here, we investigated how functional TAC-CYP3A genetic variants (CYP3A4*22/CYP3A5*3) influence the main baseline clinical and immunological risk factors of biopsy-proven acute rejection (BPAR) by means of preformed donor-specific antibodies (DSAs) and donor-specific alloreactive T cells (DSTs) in a large European cohort of 447 kidney transplants receiving TAC-based immunosuppression. A total of 70 (15.7%) patients developed BPAR. Preformed DSAs and DSTs were observed in 12 (2.7%) and 227 (50.8%) patients, respectively. According to the different CYP3A4*22 and CYP3A5*3 functional allele variants, we found 4 differential new clusters impacting fasting TAC exposure after transplantation; 7 (1.6%) were classified as high metabolizers 1 (HM1), 71 (15.9%) as HM2, 324 (72.5%) as intermediate (IM), and 45 (10.1%) as poor metabolizers (PM1). HM1/2 showed significantly lower TAC trough levels and higher dose requirements than IM and PM (p < 0.001) and more frequently showed TAC underexposure (<5 ng/ml). Multivariate Cox regression analyses revealed that CYP3A HM1 and IM pharmacogenetic phenotypes (hazard ratio (HR) 12.566, 95% CI 1.99-79.36, p = 0.007, and HR 4.532, 95% CI 1.10-18.60, p = 0.036, respectively), preformed DSTs (HR 3.482, 95% CI 1.99-6.08, p < 0.001), DSAs (HR 4.421, 95% CI 1.63-11.98, p = 0.003), and delayed graft function (DGF) (HR 2.023, 95% CI 1.22-3.36, p = 0.006) independently predicted BPAR. Notably, a significant interaction between T-cell depletion and TAC underexposure was observed, showing a reduction of the BPAR risk (HR 0.264, 95% CI 0.08-0.92, p = 0.037). Such variables except for DSAs displayed a higher predictive risk for the development of T cell-mediated rejection (TCMR). Refinement of pretransplant monitoring by incorporating TAC CYP3A SNPs with preformed DSAs as well as DSTs may improve current rejection-risk stratification and help induction treatment decision-making.

• MeSH
• cytochrom P-450 CYP3A * genetika   imunologie   metabolismus   MeSH
• hodnocení rizik MeSH
• jednonukleotidový polymorfismus MeSH
• lidé MeSH
• paměťové B-buňky * imunologie   MeSH
• T-lymfocyty * imunologie   MeSH
• takrolimus * farmakologie   terapeutické užití   MeSH
• transplantace ledvin * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

SCOPE: CYP3A4 is the most important drug-metabolizing enzyme regulated via the vitamin D receptor (VDR) in the intestine. However, less is known about VDR in the regulation of CYP3A4 and other drug-metabolizing enzymes in the liver. METHODS AND RESULTS: This study investigates whether 1α,25-dihydroxyvitamin D3 (1α,25(OH)2 D3 ) regulates major cytochrome P450 enzymes, selected phase I and II enzymes, and transporters involved in xenobiotic and steroidal endobiotic metabolism in 2D and 3D cultures of human hepatocytes. The authors found that 1α,25(OH)2 D3 increases hepatic CYP3A4 expression and midazolam 1'-hydroxylation activity in 2D hepatocytes. The results are confirmed in 3D spheroids, where 1α,25(OH)2 D3 has comparable effect on CYP3A4 mRNA expression as 1α-hydroxyvitamin D3 , an active vitamin D metabolite. Other regulated genes such as CYP1A2, AKR1C4, SLC10A1, and SLCO4A1 display only mild changes in mRNA levels after 1α,25(OH)2 D3 treatment in 2D hepatocytes. Expression of other cytochrome P450, phase I and phase II enzyme, or transporter genes are not significantly influenced by 1α,25(OH)2 D3 . Additionally, the effect of VDR activation on CYP3A4 mRNA expression is abolished by natural dietary compound sulforaphane, a common suppressor of pregnane X receptor (PXR) and constitutive androstane receptor (CAR). CONCLUSION: This study proposes that VDR or vitamin D supplementation is unlikely to significantly influence liver detoxification enzymes apart from CYP3A4.

• MeSH
• cytochrom P-450 CYP3A * genetika   MeSH
• hepatocyty MeSH
• lidé MeSH
• messenger RNA MeSH
• receptory kalcitriolu genetika   MeSH
• stanovení celkové genové exprese MeSH
• systém (enzymů) cytochromů P-450 genetika   MeSH
• vitamin D farmakologie   MeSH
• xenobiotika * farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Piscine cytochrome P450 (CYP) enzymes play an important role in the metabolism of xenobiotics. Xenobiotics often act as inducers of CYP1A1 and CYP3A expression and activity in fish. We compared constitutive mRNA expression of CYP1A1, CYP3A27, and CYP3A45 and catalytic activity of CYP1A (7-ethoxyresorufin-O-deethylation, EROD) and CYP3A-like (benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylation, BFCOD) enzymes in the following six rainbow trout tissues: liver, gill, heart, brain, intestine, and gonad. mRNA expression and activity were present in all investigated tissues. The CYP1A1 mRNA expression was higher in the liver, gill, heart, and brain compared to gonad and intestine. The intestine was the main site of CYP3A27 and CYP3A45 expression. The highest EROD and BFCOD activity was observed in liver tissue followed in descending order by heart, brain, gill, intestine, and gonad. Such differences might be related to the role of CYP physiological functions in the specific tissue. Rainbow trout exposure to 50 mg/kg of β-naphthoflavone for 48 h resulted in a 7.5- and 5.9-fold increase in liver EROD and BFCOD activity, respectively. In vitro EROD activity inhibition with ellipticine showed tissue-specific inhibition, while ketoconazole decreased BFCOD activity by 50-98 % in all tissues. Further studies are needed to identify all CYP isoforms that are responsible for these activities and modes of regulation.

• MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• játra enzymologie   MeSH
• messenger RNA genetika   metabolismus   MeSH
• mozek enzymologie   MeSH
• myokard enzymologie   MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• pohlavní dimorfismus MeSH
• regulace genové exprese enzymů fyziologie   MeSH
• střeva enzymologie   MeSH
• žábry enzymologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The interplays between the metabolic products of intestinal microbiota and the host signaling through xenobiotic receptors, including pregnane X receptor (PXR), are of growing interest, in the context of intestinal health and disease. A distinct class of microbial catabolites is formed from dietary tryptophan, having the indole scaffold in their core structure, which is a biologically active entity. In the current study, we examined a series of ten tryptophan microbial catabolites for their interactions with PXR signaling. Utilizing a reporter gene assay, we identified indole (IND) and indole-3-acetamide (IAD) as PXR agonists. IND and IAD induced PXR-regulated genes CYP3A4 and MDR1 in human intestinal cancer cells. Using time-resolved fluorescence resonance energy transfer, we show that IND (IC50 292 μM) and IAD (IC50 10 μM) are orthosteric ligands of PXR. Binding of PXR in its DNA response elements was enhanced by IND and IAD, as revealed by chromatin immunoprecipitation assay. We demonstrate that tryptophan microbial intestinal metabolites IND and IAD are ligands and agonists of human PXR. These findings are of particular importance in understanding the roles of microbial catabolites in human physiology and pathophysiology. Furthermore, these results are seminal in expanding potential drug repertoire through microbial metabolic mimicry.

• MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• indoly metabolismus   MeSH
• kultivované buňky MeSH
• kyseliny indoloctové metabolismus   MeSH
• lidé MeSH
• ligandy MeSH
• nádorové buněčné linie MeSH
• P-glykoproteiny genetika   metabolismus   MeSH
• pregnanový X receptor agonisté   genetika   MeSH
• reportérové geny MeSH
• střevní mikroflóra * MeSH
• střevní sliznice * metabolismus   mikrobiologie   MeSH
• transfekce MeSH
• tryptofan metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Dietary and microbial indoles can act as ligands and activators of pregnane X receptor (PXR), with implications in human intestinal health. In the current study, we examined the effects of simple mono-methylated indoles (MMIs) on the activity and function of PXR, using a series of human hepatic and intestinal cell models. Indoles 1-MMI and 2-MMI strongly induced CYP3A4 and MDR1 mRNAs in human intestinal adenocarcinoma cells LS180, but not in primary human hepatocytes. The levels of CYP3A4 mRNA were increased by 1-MMI and 2-MMI in wild type, but not in PXR-knock-out human hepatic progenitor HepaRG cells, implying the involvement of PXR in CYP3A4 induction by MMIs. Utilizing reporter gene assay, we observed dose-dependent activation of PXR by all MMIs, and their efficacies and potencies were comparable. Tested MMIs also displayed moderate antagonist effects on PXR, revealing about partial agonist effects of these compounds. As demonstrated using the Chromatin immunoprecipitation assay (ChIP),1-MMI increased PXR occupancy of the CYP3A4 promoter. Time-Resolved Fluorescence Resonance Energy Transfer revealed that MMIs are weak ligands of human PXR. Collectively, we show that MMIs are ligands and partial agonists of human PXR, which induce PXR-regulated genes in human intestinal cells.

• MeSH
• cytochrom P-450 CYP3A genetika   fyziologie   MeSH
• hepatocyty účinky léků   metabolismus   MeSH
• indoly metabolismus   farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• P-glykoproteiny genetika   MeSH
• pregnanový X receptor účinky léků   genetika   metabolismus   MeSH
• promotorové oblasti (genetika) MeSH
• signální transdukce účinky léků   MeSH
• střevní sliznice cytologie   účinky léků   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The selection of a suitable combination of reference genes (RGs) for data normalization is a crucial step for obtaining reliable and reproducible results from transcriptional response analysis using a reverse transcription-quantitative polymerase chain reaction. This is especially so if a three-dimensional multicellular model prepared from liver tissues originating from biologically diverse human individuals is used. The mRNA and miRNA RGs stability were studied in thirty-five human liver tissue samples and twelve precision-cut human liver slices (PCLS) treated for 24 h with dimethyl sulfoxide (controls) and PCLS treated with β-naphthoflavone (10 μM) or rifampicin (10 μM) as cytochrome P450 (CYP) inducers. Validation of RGs was performed by an expression analysis of CYP3A4 and CYP1A2 on rifampicin and β-naphthoflavone induction, respectively. Regarding mRNA, the best combination of RGs for the controls was YWHAZ and B2M, while YWHAZ and ACTB were selected for the liver samples and treated PCLS. Stability of all candidate miRNA RGs was comparable or better than that of generally used short non-coding RNA U6. The best combination for the control PCLS was miR-16-5p and miR-152-3p, in contrast to the miR-16-5b and miR-23b-3p selected for the treated PCLS. Our results showed that the candidate RGs were rather stable, especially for miRNA in human PCLS.

• MeSH
• beta-2-mikroglobulin genetika   metabolismus   MeSH
• beta-naftoflavon farmakologie   MeSH
• cytochrom P-450 CYP1A2 genetika   metabolismus   MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• dimethylsulfoxid farmakologie   MeSH
• dospělí MeSH
• játra účinky léků   metabolismus   MeSH
• kvantitativní polymerázová řetězová reakce normy   MeSH
• lidé středního věku MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mikro RNA genetika   metabolismus   MeSH
• proteiny 14-3-3 genetika   metabolismus   MeSH
• referenční standardy MeSH
• rifampin farmakologie   MeSH
• senioři MeSH
• stanovení celkové genové exprese normy   MeSH
• systém (enzymů) cytochromů P-450 farmakologie   MeSH
• transkriptom MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Various antiplatelet drugs are used following Acute Coronary Syndromes (ACS). Of them, adenosine diphosphate receptor P2Y12 inhibitors clopidogrel, prasugrel and ticagrelor are currently used for post-ACS long-term treatment. Although they act on the same receptor, they differ in pharmacodynamics and pharmacokinetics. Several enzymes and transporters involved in the metabolism of P2Y12 inhibitors show genetic variability with functional impact. This includes Pglycoprotein, carboxylesterase 1 and, most notably, CYP2C19 that is important in clopidogrel activation. Common gain-of-function or loss-of-function alleles of CYP2C19 gene are associated with lower or higher platelet reactivity that may impact clinical outcomes of clopidogrel treatment. Prasugrel is considered to be less dependent on CYP2C19 variability as it is also metabolized by other CYP450 isoforms. Some studies, however, showed the relevance of CYP2C19 variants for platelet reactivity during prasugrel treatment as well. Ticagrelor is metabolized mainly by CYP3A4, which does not show functionally relevant genetic variability. Its concentrations may be modified by the variants of Pglycoprotein gene ABCB1. While no substantial difference between the clinical efficacy of prasugrel and ticagrelor has been documented, both of them have been shown to be superior to clopidogrel in post-ACS treatment. This can be partially explained by lower variability at each step of their metabolism. It is probable that factors influencing the pharmacokinetics of both drugs, including genetic factors, may predict the clinical efficacy of antiplatelet treatment in personalized medicine. CONCLUSION: We summarize the pharmacokinetics and pharmacogenetics of P2Y12 inhibitors with respect to their clinical effects in post-myocardial infarction treatment.

• MeSH
• biotransformace genetika   MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• cytochrom P450 CYP2C19 genetika   metabolismus   MeSH
• farmakogenomické varianty * MeSH
• infarkt myokardu krev   diagnóza   farmakoterapie   MeSH
• inhibitory agregace trombocytů škodlivé účinky   farmakokinetika   terapeutické užití   MeSH
• klopidogrel škodlivé účinky   farmakokinetika   terapeutické užití   MeSH
• léková rezistence genetika   MeSH
• lidé MeSH
• P-glykoproteiny genetika   metabolismus   MeSH
• prasugrel hydrochlorid škodlivé účinky   farmakokinetika   terapeutické užití   MeSH
• purinergní receptory P2Y - antagonisté škodlivé účinky   farmakokinetika   terapeutické užití   MeSH
• purinergní receptory P2Y12 krev   účinky léků   MeSH
• ticagrelor škodlivé účinky   farmakokinetika   terapeutické užití   MeSH
• trombocyty účinky léků   metabolismus   MeSH
• výsledek terapie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

1. Humans and animals are commonly exposed to indole-3-carbinol (I3C) and resveratrol (RES) via food or beverages. Moreover, these compounds have been demonstrated to potentially cause food-drug interactions. However, information about their combined effects is limited. Therefore, we investigated the effects of I3C and RES, both as single compounds and in combination, on cytochrome P450 1A and 3A activity and gene expression. 2. Using porcine microsomes, we demonstrated that RES caused non-competitive inhibition of CYP1A activity and un-competitive inhibition of CYP3A activity. Compared to the effect of single compounds, co-treatment with I3C and RES increased a degree of inhibition of CYP1A activity. 3. In porcine primary hepatocytes, treatment with I3C and RES resulted in induction of CYP1A1, CYP1A2 and CYP3A29 mRNA expression. 4. In conclusion, we demonstrated that both RES and I3C could cause food-drug interactions and that the combined effect could be more potent in doing so.

• MeSH
• cytochrom P-450 CYP1A1 antagonisté a inhibitory   metabolismus   MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• hepatocyty účinky léků   MeSH
• indoly farmakologie   MeSH
• inhibitory cytochromu P450 CYP3A farmakologie   MeSH
• interakce mezi potravou a léky MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• prasata MeSH
• receptory aromatických uhlovodíků genetika   MeSH
• regulace genové exprese enzymů účinky léků   MeSH
• steroidní receptory genetika   MeSH
• stilbeny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The Pregnane X (PXR), Vitamin D (VDR) and Farnesoid X (FXR) nuclear receptors have been shown to be receptors of bile acids controlling their detoxification or synthesis. Chenodeoxycholic (CDCA) and lithocholic (LCA) acids are ligands of FXR and VDR, respectively, whereas 3-keto and acetylated derivates of LCA have been described as ligands for all three receptors. In this study, we hypothesized that oxidation or acetylation at position 3, 7 and 12 of bile acids DCA (deoxycholic acid), LCA, CA (cholic acid), and CDCA by detoxification enzymes or microbiome may have an effect on the interactions with bile acid nuclear receptors. We employed reporter gene assays in HepG2 cells, the TR-FRET assay with recombinant PXR and RT-PCR to study the effects of acetylated and keto bile acids on the nuclear receptors activation and their target gene expression in differentiated hepatic HepaRG cells. We demonstrate that the DCA 3,12-diacetate and CA 3,7,12-triacetate derivatives are ligands of PXR and DCA 3,12-diacetate induces PXR target genes such as CYP3A4, CYP2B6 and ABCB1/MDR1. In conclusion, we found that acetylated DCA and CA are potent ligands of PXR. Whether the acetylated bile acid derivatives are novel endogenous ligands of PXR with detoxification or physiological functions should be further studied in ongoing experiments.

• MeSH
• acetylace MeSH
• buněčné kultury MeSH
• buňky Hep G2 MeSH
• cytochrom P-450 CYP3A genetika   MeSH
• cytochrom P450 CYP2B6 genetika   MeSH
• hepatocyty účinky léků   enzymologie   metabolismus   MeSH
• kyselina cholová chemie   metabolismus   farmakologie   MeSH
• kyselina deoxycholová chemie   metabolismus   farmakologie   MeSH
• lidé MeSH
• ligandy MeSH
• myši MeSH
• oxidace-redukce MeSH
• P-glykoprotein genetika   MeSH
• plazmidy MeSH
• receptory cytoplazmatické a nukleární chemie   genetika   metabolismus   MeSH
• receptory kalcitriolu chemie   genetika   metabolismus   MeSH
• reportérové geny MeSH
• simulace molekulového dockingu MeSH
• steroidní receptory chemie   genetika   metabolismus   MeSH
• techniky dvojhybridového systému MeSH
• transfekce MeSH
• vazba proteinů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH