In spite of remarkable reduction in the number of children born with HIV due to antiretroviral therapy, concerns remain on the short- and long-term effects of antiretroviral drugs at the feto-placental unit. Cardio- and skeletal myopathies have been reported in children exposed to antiretroviral drugs prenatally. These conditions have also been described in perturbed placental transfer of l-carnitine, an essential co-factor in fatty acid oxidation. Due to limited fetal and placental synthesis, carnitine supply is maintained through the placental carnitine uptake from maternal blood by the organic cation/carnitine transporters OCTN1 and OCTN2 (SLC22A4 and SLC22A5, respectively). The aim of our study was to investigate potential inhibition of placental carnitine uptake by a broad range of antiretroviral drugs comprising nucleoside/nucleotide reverse transcriptase inhibitors (lamivudine, zidovudine, abacavir, tenofovir disoproxil fumarate), non-nucleoside reverse transcriptase inhibitors (rilpivirine, efavirenz, etravirine), protease inhibitors (ritonavir, lopinavir, atazanavir, saquinavir, tipranavir), integrase inhibitors (raltegravir, dolutegravir, elvitegravir) and viral entry inhibitor, maraviroc. Studies in choriocarcinoma BeWo cells and human placenta-derived models confirmed predominant expression and function of OCTN2 above OCTN1 in l-carnitine transport. Subsequent screenings in BeWo cells and isolated MVM vesicles revealed seven antiretroviral drugs as inhibitors of the Na+-dependent l-carnitine uptake, corresponding to OCTN2. Ritonavir, saquinavir and elvitegravir showed the highest inhibitory potential which was further confirmed for ritonavir and saquinavir in placental fresh villous fragments. Our data indicate possible impairment in placental and fetal supply of l-carnitine with ritonavir and saquinavir, while suggesting retained placental carnitine transport with the other antiretroviral drugs.

• MeSH
• antiretrovirové látky toxicita   MeSH
• biologický transport MeSH
• hodnocení rizik MeSH
• karnitin metabolismus   MeSH
• lidé MeSH
• matka - expozice noxám škodlivé účinky   MeSH
• nádorové buněčné linie MeSH
• placenta účinky léků   metabolismus   MeSH
• proteiny přenášející organické kationty antagonisté a inhibitory   metabolismus   MeSH
• rodina nosičů rozpuštěných látek 22, člen 5 antagonisté a inhibitory   metabolismus   MeSH
• těhotenství MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

OBJECTIVE: A prominent, safe and efficient therapy for patients with chronic myeloid leukemia (CML) is inhibiting oncogenic protein BCR::ABL1 in a targeted manner with imatinib, a tyrosine kinase inhibitor. A substantial part of patients treated with imatinib report skeletomuscular adverse events affecting their quality of life. OCTN2 membrane transporter is involved in imatinib transportation into the cells. At the same time, the crucial physiological role of OCTN2 is cellular uptake of carnitine which is an essential co-factor for the mitochondrial β-oxidation pathway. This work investigates the impact of imatinib treatment on carnitine intake and energy metabolism of muscle cells. METHODS: HTB-153 (human rhabdomyosarcoma) cell line and KCL-22 (CML cell line) were used to study the impact of imatinib treatment on intracellular levels of carnitine and vice versa. The energy metabolism changes in cells treated by imatinib were quantified and compared to changes in cells exposed to highly specific OCTN2 inhibitor vinorelbine. Mouse models were used to test whether in vitro observations are also achieved in vivo in thigh muscle tissue. The analytes of interest were quantified using a Prominence HPLC system coupled with a tandem mass spectrometer. RESULTS: This work showed that through the carnitine-specific transporter OCTN2, imatinib and carnitine intake competed unequally and intracellular carnitine concentrations were significantly reduced. In contrast, carnitine preincubation did not influence imatinib cell intake or interfere with leukemia cell targeting. Blocking the intracellular supply of carnitine with imatinib significantly reduced the production of most Krebs cycle metabolites and ATP. However, subsequent carnitine supplementation rescued mitochondrial energy production. Due to specific inhibition of OCTN2 activity, the influx of carnitine was blocked and mitochondrial energy metabolism was impaired in muscle cells in vitro and in thigh muscle tissue in a mouse model. CONCLUSIONS: This preclinical experimental study revealed detrimental effect of imatinib on carnitine-mediated energy metabolism of muscle cells providing a possible molecular background of the frequently occurred side effects during imatinib therapy such as fatigue, muscle pain and cramps.

• MeSH
• antitumorózní látky škodlivé účinky   farmakologie   MeSH
• chronická myeloidní leukemie * farmakoterapie   metabolismus   MeSH
• energetický metabolismus účinky léků   MeSH
• imatinib mesylát * farmakologie   škodlivé účinky   MeSH
• inhibitory proteinkinas farmakologie   škodlivé účinky   MeSH
• karnitin * metabolismus   farmakologie   MeSH
• lidé MeSH
• mitochondrie metabolismus   účinky léků   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• rodina nosičů rozpuštěných látek 22, člen 5 * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Through high-throughput next-generation sequencing of promoters of solute carrier and ATP-binding cassette genes, which encode drug transporters, we aimed to identify SNPs associated with the response to imatinib administered for first-line treatment of patients with chronic myeloid leukemia. METHODS: In silico analysis using publicly available databases was done to select the SLC and ABC genes and their promoters for the next-generation sequencing. SNPs associated with the imatinib response were identified using Fisher's exact probability tests and subjected to the linkage disequilibrium analyses with regulatory loci of concerned genes. We analyzed cumulative achievement of major molecular response and probability of event free survival in relation to identified SNP genotypes in 129 CML patients and performed multivariate analysis for determination of genotypes as independent predictors of outcome. Gene expression analysis of eight cell lines naturally carrying different genotypes was performed to outline an impact of genotypes on the gene expression. RESULTS: We observed significant differences in the frequencies of the rs460089-GC and rs460089-GG (SLC22A4) genotypes among rs2631365-TC (SLC22A5) genotype carriers that were associated with optimal and non-optimal responses, respectively. Loci rs460089 and rs2631365 were in highly significant linkage disequilibrium with 12 regulatory loci in introns of SLC22A4 and SLC22A5 encoding imatinib transporters. Genotype association analysis with the response to imatinib indicated that rs460089-GC carriers had a significantly higher probability of achieving a stable major molecular response (BCR-ABL1 transcript level below or equal to 0.1% in the international scale). In contrast, the rs460089-GG represented a risk factor for imatinib failure, which was significantly higher in rs460089-GG_rs2631365-TC carriers. CONCLUSIONS: This exploratory study depicted potentially important genetic markers predicting outcome of imatinib treatment, which may be helpful for tailoring therapy in clinical practice.

• MeSH
• antitumorózní látky aplikace a dávkování   terapeutické užití   MeSH
• buňky K562 MeSH
• chronická myeloidní leukemie farmakoterapie   genetika   MeSH
• genotyp MeSH
• imatinib mesylát aplikace a dávkování   terapeutické užití   MeSH
• jednonukleotidový polymorfismus * MeSH
• lidé MeSH
• mutační rychlost MeSH
• nádorové buněčné linie MeSH
• promotorové oblasti (genetika) MeSH
• proteiny přenášející organické kationty genetika   MeSH
• rodina nosičů rozpuštěných látek 22, člen 5 genetika   MeSH
• sekvenční analýza DNA metody   MeSH
• vazebná nerovnováha MeSH
• výsledek terapie MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH