Carbonyl-reducing enzymes (CREs) catalyse the reduction of carbonyl groups in many eobiotic and xenobiotic compounds in all organisms, including helminths. Previous studies have shown the important roles of CREs in the deactivation of several anthelmintic drugs (e.g., flubendazole and mebendazole) in adults infected with the parasitic nematode Haemonchus contortus, in which the activity of a CRE is increased in drug-resistant strains. The aim of the present study was to compare the abilities of nematodes of both a drug-susceptible strain (ISE) and a drug-resistant strain (IRE) to reduce the carbonyl group of flubendazole (FLU) in different developmental stages (eggs, L1/2 larvae, L3 larvae, and adults). In addition, the effects of selected CRE inhibitors (e.g., glycyrrhetinic acid, naringenin, silybin, luteolin, glyceraldehyde, and menadione) on the reduction of FLU were evaluated in vitro and ex vivo in H. contortus adults. The results showed that FLU was reduced by H. contortus in all developmental stages, with adult IRE females being the most metabolically active. Larvae (L1/2 and L3) and adult females of the IRE strain reduced FLU more effectively than those of the ISE strain. Data from the in vitro inhibition study (performed with cytosolic-like fractions of H. contortus adult homogenate) revealed that glycyrrhetinic acid, naringenin, mebendazole and menadione are effective inhibitors of FLU reduction. Ex vivo study data showed that menadione inhibited FLU reduction and also decreased the viability of H. contortus adults to a similar extent. Naringenin and mebendazole were not toxic at the concentrations tested, but they did not inhibit the reduction of FLU in adult worms ex vivo.

• Klíčová slova
• Anthelmintics, Strongyloides, drug biotransformation, helminths, inhibitors,
• MeSH
• anthelmintika * farmakologie   terapeutické užití   MeSH
• Haemonchus * MeSH
• kyselina glycyrhetinová * farmakologie   MeSH
• larva MeSH
• mebendazol farmakologie   terapeutické užití   MeSH
• vitamin K 3 farmakologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anthelmintika * MeSH
• flubendazole MeSH Prohlížeč
• kyselina glycyrhetinová * MeSH
• mebendazol MeSH
• vitamin K 3 MeSH

Midostaurin is an FMS-like tyrosine kinase 3 receptor (FLT3) inhibitor that provides renewed hope for treating acute myeloid leukaemia (AML). The limited efficacy of this compound as a monotherapy contrasts with that of its synergistic combination with standard cytarabine and daunorubicin (Dau), suggesting a therapeutic benefit that is not driven only by FLT3 inhibition. In an AML context, the activity of the enzyme aldo-keto reductase 1C3 (AKR1C3) is a crucial factor in chemotherapy resistance, as it mediates the intracellular transformation of anthracyclines to less active hydroxy metabolites. Here, we report that midostaurin is a potent inhibitor of Dau inactivation mediated by AKR1C3 in both its recombinant form as well as during its overexpression in a transfected cell model. Likewise, in the FLT3- AML cell line KG1a, midostaurin was able to increase the cellular accumulation of Dau and significantly decrease its metabolism by AKR1C3 simultaneously. The combination of those mechanisms increased the nuclear localization of Dau, thus synergizing its cytotoxic effects on KG1a cells. Our results provide new in vitro evidence of how the therapeutic activity of midostaurin could operate beyond targeting the FLT3 receptor.

• Klíčová slova
• AKR1C3, AML therapy, Anthracyclines, Midostaurin, Multidrug resistance,
• MeSH
• akutní myeloidní leukemie farmakoterapie   enzymologie   genetika   patologie   MeSH
• biotransformace MeSH
• daunomycin metabolismus   farmakologie   MeSH
• HCT116 buňky MeSH
• inhibitory enzymů farmakologie   MeSH
• kolorektální nádory farmakoterapie   enzymologie   genetika   patologie   MeSH
• lidé MeSH
• protein AKR1C3 antagonisté a inhibitory   genetika   metabolismus   MeSH
• protokoly protinádorové kombinované chemoterapie farmakologie   MeSH
• staurosporin analogy a deriváty   farmakologie   MeSH
• synergismus léků MeSH
• tyrosinkinasa 3 podobná fms antagonisté a inhibitory   genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AKR1C3 protein, human MeSH Prohlížeč
• daunomycin MeSH
• FLT3 protein, human MeSH Prohlížeč
• inhibitory enzymů MeSH
• midostaurin MeSH Prohlížeč
• protein AKR1C3 MeSH
• staurosporin MeSH
• tyrosinkinasa 3 podobná fms MeSH

Olaparib is a potent poly (ADP-ribose) polymerase inhibitor currently used in targeted therapy for treating cancer cells with BRCA mutations. Here we investigate the possible interference of olaparib with daunorubicin (Daun) metabolism, mediated by carbonyl-reducing enzymes (CREs), which play a significant role in the resistance of cancer cells to anthracyclines. Incubation experiments with the most active recombinant CREs showed that olaparib is a potent inhibitor of the aldo-keto reductase 1C3 (AKR1C3) enzyme. Subsequent inhibitory assays in the AKR1C3-overexpressing cellular model transfected human colorectal carcinoma HCT116 cells, demonstrating that olaparib significantly inhibits AKR1C3 at the intracellular level. Consequently, molecular docking studies have supported these findings and identified the possible molecular background of the interaction. Drug combination experiments in HCT116, human liver carcinoma HepG2, and leukemic KG1α cell lines showed that this observed interaction can be exploited for the synergistic enhancement of Daun's antiproliferative effect. Finally, we showed that olaparib had no significant effect on the mRNA expression of AKR1C3 in HepG2 and KG1α cells. In conclusion, our data demonstrate that olaparib interferes with anthracycline metabolism, and suggest that this phenomenon might be utilized for combating anthracycline resistance.

• Klíčová slova
• HepG2, KG1α, anti-proliferative, daunorubicin, leukaemia, olaparib, synergistic,
• Publikační typ
• časopisecké články MeSH

Pharmacotherapy of acute myeloid leukemia (AML) remains challenging, and the disease has one of the lowest curability rates among hematological malignancies. The therapy outcomes are often compromised by the existence of a resistant AML phenotype associated with overexpression of ABCB1 and ABCG2 transporters. Because AML induction therapy frequently consists of anthracycline-like drugs, their efficiency may also be diminished by drug biotransformation via carbonyl reducing enzymes (CRE). In this study, we investigated the modulatory potential of the CDK4/6 inhibitors abemaciclib, palbociclib, and ribociclib on AML resistance using peripheral blood mononuclear cells (PBMC) isolated from patients with de novo diagnosed AML. We first confirmed inhibitory effect of the tested drugs on ABCB1 and ABCG2 in ABC transporter-expressing resistant HL-60 cells while also showing the ability to sensitize the cells to cytotoxic drugs even as no effect on AML-relevant CRE isoforms was observed. All tested CDK4/6 inhibitors elevated mitoxantrone accumulations in CD34+ PBMC and enhanced accumulation of mitoxantrone was found with abemaciclib and ribociclib in PBMC of FLT3-ITD- patients. Importantly, the accumulation rate in the presence of CDK4/6 inhibitors positively correlated with ABCB1 expression in CD34+ patients and led to enhanced apoptosis of PBMC in contrast to CD34- samples. In summary, combination therapy involving CDK4/6 inhibitors could favorably target multidrug resistance, especially when personalized based on CD34- and ABCB1-related markers.

• Klíčová slova
• ABC transporters, CDK4/6 inhibitors, acute myeloid leukemia, drug resistance,
• Publikační typ
• časopisecké články MeSH

Sesquiterpenes, 15-carbon compounds formed from three isoprenoid units, are the main components of plant essential oils. Sesquiterpenes occur in human food, but they are principally taken as components of many folk medicines and dietary supplements. The aim of our study was to test and compare the potential inhibitory effect of acyclic sesquiterpenes, trans-nerolidol, cis-nerolidol and farnesol, on the activities of the main xenobiotic-metabolizing enzymes in rat and human liver in vitro. Rat and human subcellular fractions, relatively specific substrates, corresponding coenzymes and HPLC, spectrophotometric or spectrofluorometric analysis of product formation were used. The results showed significant inhibition of cytochromes P450 (namely CYP1A, CYP2B and CYP3A subfamilies) activities by all tested sesquiterpenes in rat as well as in human hepatic microsomes. On the other hand, all tested sesquiterpenes did not significantly affect the activities of carbonyl-reducing enzymes and conjugation enzymes. The results indicate that acyclic sesquiterpenes might affect CYP1A, CYP2B and CYP3A mediated metabolism of concurrently administered drugs and other xenobiotics. The possible drug-sesquiterpene interactions should be verified in in vivo experiments.

• Klíčová slova
• drug-metabolizing enzymes, farnesol, inhibition, nerolidol,
• MeSH
• farnesol chemie   farmakologie   MeSH
• inhibiční koncentrace 50 MeSH
• inhibitory cytochromu P450 chemie   farmakologie   MeSH
• játra enzymologie   MeSH
• kinetika MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• seskviterpeny chemie   farmakologie   MeSH
• subcelulární frakce enzymologie   MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• xenobiotika metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• farnesol MeSH
• inhibitory cytochromu P450 MeSH
• nerolidol MeSH Prohlížeč
• seskviterpeny MeSH
• systém (enzymů) cytochromů P-450 MeSH
• xenobiotika MeSH