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
PURPOSE: S-(4-Nitrobenzyl)-6-thioinosine (NBMPR) is routinely used at concentrations of 0.10 μM and 0.10 mM to specifically inhibit transport of nucleosides mediated by equilibrative nucleoside transporters 1 (ENT1) and 2 (ENT2), respectively. We recently showed that NBMPR (0.10 mM) might also inhibit placental active efflux of [3H]zidovudine and [3H]tenofovir disoproxil fumarate. Here we test the hypothesis that NBMPR abolishes the activity of P-glycoprotein (ABCB1) and/or breast cancer resistance protein (ABCG2). METHODS: We performed accumulation assays with Hoechst 33342 (a model dual substrate of ABCB1 and ABCG2) and bi-directional transport studies with the ABCG2 substrate [3H]glyburide in transduced MDCKII cells, accumulation studies in choriocarcinoma-derived BeWo cells, and in situ dual perfusions of rat term placenta with glyburide. RESULTS: NBMPR inhibited Hoechst 33342 accumulation in MDCKII-ABCG2 cells (IC50 = 53 μM) but not in MDCKII-ABCB1 and MDCKII-parental cells. NBMPR (0.10 mM) also inhibited bi-directional [3H]glyburide transport across monolayers of MDCKII-ABCG2 cells and blocked ABCG2-mediated [3H]glyburide efflux by rat term placenta in situ. CONCLUSION: NBMPR at a concentration of 0.10 mM abolishes ABCG2 activity. Researchers using NBMPR to evaluate the effect of ENTs on pharmacokinetics must therefore interpret their results carefully if studying compounds that are substrates of both ENTs and ABCG2.
- MeSH
- ABC transportér z rodiny G, člen 2 antagonisté a inhibitory metabolismus MeSH
- antivirové látky metabolismus farmakokinetika MeSH
- biologický transport účinky léků MeSH
- buněčné linie MeSH
- buňky MDCK MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- nádorové proteiny antagonisté a inhibitory metabolismus MeSH
- P-glykoproteiny antagonisté a inhibitory metabolismus MeSH
- placenta účinky léků metabolismus MeSH
- potkani Wistar MeSH
- psi MeSH
- těhotenství MeSH
- thioinosin analogy a deriváty farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- psi MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Brivanib, a promising tyrosine kinase inhibitor, is currently undergoing advanced stages of clinical evaluation for solid tumor therapy. In this work, we investigated possible interactions of this novel drug candidate with ABC drug efflux transporters and cytochrome P450 (CYP450) drug-metabolizing enzymes that participate in cancer multidrug resistance (MDR) and pharmacokinetic drug-drug interactions (DDIs). First, in accumulation experiments with various model substrates, we identified brivanib as an inhibitor of the ABCB1, ABCG2, and ABCC1 transporters. However, in subsequent combination studies employing 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide proliferation assays in both Madin-Darby canine kidney II (MDCKII) and A431 cellular models, only ABCG2 inhibition was revealed to be able to synergistically potentiate mitoxantrone effects. Advantageous to its possible use as MDR antagonist, brivanib's chemosensitizing properties were not impaired by activity of any of the MDR-associated ABC transporters, as observed in comparative viability assay in the MDCKII cell sublines. In incubation experiments with eight recombinant CYP450s, we found that brivanib potently inhibited CYP2C subfamily members and the CYP2B6 isoform. Finally, in induction studies, we demonstrated that brivanib upregulated ABCB1 and CYP1A2 messenger RNA levels in systemic cell models, although this interaction was not significantly manifested at a functional level. In conclusion, brivanib exhibits potential to cause clinically relevant pharmacokinetic DDIs and act as a modulator of ABCG2-mediated MDR. Our findings might be used as an important background for subsequent in vivo investigations and pave the way for the safe and effective use of brivanib in oncological patients.
- MeSH
- ABC transportér z rodiny G, člen 2 antagonisté a inhibitory MeSH
- alanin analogy a deriváty farmakologie MeSH
- biotransformace účinky léků MeSH
- buněčné linie MeSH
- buňky MDCK MeSH
- chemorezistence účinky léků MeSH
- inhibitory cytochromu P450 farmakologie MeSH
- lékové interakce fyziologie MeSH
- lidé MeSH
- mnohočetná léková rezistence účinky léků MeSH
- nádorové proteiny antagonisté a inhibitory MeSH
- P-glykoproteiny metabolismus MeSH
- psi MeSH
- systém (enzymů) cytochromů P-450 metabolismus MeSH
- triaziny farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Etoposide is a well-known and widely used anticancer drug that displays several side effects. In addition, tumors often acquire resistance to this drug. Our aim is to develop a combination therapy that would augment toxicity of etoposide in malignant cells. Based on literature and our experiments, we selected mifepristone (RU486) as a potential supporting molecule that is able to enhance etoposide toxicity against cancer cells. All experiments were performed with Hep G2 cells, a well-known and described human hepatocellular carcinoma cell line. By using xCELLigence system, we demonstrated that mifepristone enhances toxicity of etoposide in a dose dependent manner with concomitant caspase-3 activity. We evaluated upregulation of Bax because mifepristone was demonstrated to modulate proapoptotic Bax protein expression. Our data show only weak and not statistically significant increase of Bax expression. On the other hand, we show that mifepristone increases etoposide toxicity via inhibition of ABC transporters, coupled with significant increase of intracellular etoposide concentration. In conclusion, we demonstrate that mifepristone has a synergistic effect with etoposide treatment in the Hep G2 cells and that the effect is related to ABC transporters inhibition.
- MeSH
- ABC transportér z rodiny G, člen 2 antagonisté a inhibitory MeSH
- antitumorózní látky fytogenní farmakologie MeSH
- biologický transport účinky léků MeSH
- buňky Hep G2 MeSH
- buňky K562 MeSH
- etoposid farmakologie MeSH
- kaspasa 3 metabolismus MeSH
- lidé MeSH
- mifepriston farmakologie MeSH
- nádorové proteiny antagonisté a inhibitory MeSH
- P-glykoproteiny antagonisté a inhibitory MeSH
- protein X asociovaný s bcl-2 metabolismus MeSH
- synergismus léků MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Ribociclib is a novel cyclin-dependent kinase (CDK) 4 and 6 selective inhibitor that recently gained breakthrough therapy status and global approval for advanced breast cancer treatment. ATP-binding cassette (ABC) transporters may become a site of severe drug interactions and a mechanism of multidrug resistance (MDR) development. With respect to rapid progress of ribociclib in the clinical field, we aimed to identify its interactions with ABC transporters and cytochrome P450 (CYP) isoenzymes and evaluate its potential to overcome transporter-mediated MDR using established in vitro methods. Our data showed accelerated ABCB1 inhibitor LY335979-sensitive, basolateral-to-apical transport of ribociclib across MDCKII-ABCB1 cell monolayers, which identified ribociclib as an ABCB1 substrate. The antiproliferative studies supported this finding by demonstrating significantly higher EC50 value in ABCB1-, but not ABCG2- or ABCC1-expressing MDCKII cells, than in the parent MDCKII cell line. Furthermore, we observed significant inhibitory effects of ribociclib on ABCB1 and ABCG2 transporters and CYP1A2, CYP3A4, CYP3A5, and CYP2C9 isoform activity in human CYP-expressing insect microsomes. The ribociclib-induced ABCB1 and ABCG2 inhibition further reversed daunorubicin and mitoxantrone resistance in MDCKII and human MCF-7 breast carcinoma cell lines, indicating a synergistic antiproliferative effect, without affecting ABCB1 or ABCG2 expression. In summary, our data indicate that ABCB1 affects ribociclib transport across the membranes and the high potential of ribociclib for drug-drug interactions (DDIs) through ABCB1 and ABCG2 transporters and CYP isoforms. Moreover, we demonstrate the beneficial MDR-reversing potential of ribociclib, which could be further exploited in novel anticancer treatment strategies.
- MeSH
- ABC transportér z rodiny G, člen 2 antagonisté a inhibitory metabolismus MeSH
- aminopyridiny farmakokinetika MeSH
- buňky MDCK MeSH
- inhibitory cytochromu P450 farmakokinetika MeSH
- izoenzymy antagonisté a inhibitory metabolismus MeSH
- lékové interakce fyziologie MeSH
- lidé MeSH
- MFC-7 buňky MeSH
- nádorové proteiny antagonisté a inhibitory metabolismus MeSH
- P-glykoproteiny antagonisté a inhibitory metabolismus MeSH
- psi MeSH
- puriny farmakokinetika MeSH
- substrátová specifita účinky léků fyziologie MeSH
- systém (enzymů) cytochromů P-450 metabolismus MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH