Targeting mutations that trigger acute myeloid leukaemia (AML) has emerged as a refined therapeutic approach in recent years. Enasidenib (Idhifa) is the first selective inhibitor of mutated forms of isocitrate dehydrogenase 2 (IDH2) approved against relapsed/refractory AML. In addition to its use as monotherapy, a combination trial of enasidenib with standard intensive induction therapy (daunorubicin + cytarabine) is being evaluated. This study aimed to decipher enasidenib off-target molecular mechanisms involved in anthracycline resistance, such as reduction by carbonyl reducing enzymes (CREs) and drug efflux by ATP-binding cassette (ABC) transporters. We analysed the effect of enasidenib on daunorubicin (Daun) reduction by several recombinant CREs and different human cell lines expressing aldo-keto reductase 1C3 (AKR1C3) exogenously (HCT116) or endogenously (A549 and KG1a). Additionally, A431 cell models overexpressing ABCB1, ABCG2, or ABCC1 were employed to evaluate enasidenib modulation of Daun efflux. Furthermore, the potential synergism of enasidenib over Daun cytotoxicity was quantified amongst all the cell models. Enasidenib selectively inhibited AKR1C3-mediated inactivation of Daun in vitro and in cell lines expressing AKR1C3, as well as its extrusion by ABCB1, ABCG2, and ABCC1 transporters, thus synergizing Daun cytotoxicity to overcome resistance. This work provides in vitro evidence on enasidenib-mediated targeting of the anthracycline resistance actors AKR1C3 and ABC transporters under clinically achievable concentrations. Our findings may encourage its combination with intensive chemotherapy and even suggest that the effectiveness of enasidenib as monotherapy against AML could lie beyond the targeting of mIDH2.

• MeSH
• ATP-Binding Cassette Transporters metabolism   MeSH
• Adenosine Triphosphate MeSH
• Leukemia, Myeloid, Acute * drug therapy   genetics   MeSH
• Anthracyclines MeSH
• Cytarabine therapeutic use   MeSH
• Daunorubicin * pharmacology   MeSH
• Isocitrate Dehydrogenase genetics   metabolism   therapeutic use   MeSH
• Humans MeSH
• Antibiotics, Antineoplastic therapeutic use   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Brassinosteroids are steroidal phytohormones that regulate plant development and physiology, including adaptation to environmental stresses. Brassinosteroids are synthesized in the cell interior but bind receptors at the cell surface, necessitating a yet to be identified export mechanism. Here, we show that a member of the ATP-binding cassette (ABC) transporter superfamily, ABCB19, functions as a brassinosteroid exporter. We present its structure in both the substrate-unbound and the brassinosteroid-bound states. Bioactive brassinosteroids are potent activators of ABCB19 ATP hydrolysis activity, and transport assays showed that ABCB19 transports brassinosteroids. In Arabidopsis thaliana, ABCB19 and its close homolog, ABCB1, positively regulate brassinosteroid responses. Our results uncover an elusive export mechanism for bioactive brassinosteroids that is tightly coordinated with brassinosteroid signaling.

• MeSH
• ATP-Binding Cassette Transporters * chemistry   genetics   metabolism   MeSH
• Adenosine Triphosphate metabolism   MeSH
• Arabidopsis * genetics   metabolism   MeSH
• Brassinosteroids * metabolism   MeSH
• Protein Conformation MeSH
• Indoleacetic Acids metabolism   MeSH
• Arabidopsis Proteins * chemistry   genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH

1. Purine cyclin-dependent kinase inhibitors have recently been recognised as promising candidates for the treatment of various cancers. While pharmacodynamic properties of these compounds are relatively well understood, their pharmacokinetics including possible interactions with placental transport systems have not been characterised to date. 2. In this study, we investigated transplacental passage of olomoucine II and purvalanol A in rat focusing on possible role of p-glycoprotein (ABCB1), breast cancer resistance protein (ABCG2) and/or multidrug resistance-associated proteins (ABCCs). Employing the in situ method of dually perfused rat term placenta, we demonstrate transplacental passage of both olomoucine II and purvalanol A against the concentration gradient in foetus-to-mother direction. Using several ATP-binding cassette (ABC) drug transporter inhibitors, we confirm the participation of ABCB1, ABCG2 and ABCCs transporters in the placental passage of olomoucine II, but not purvalanol A. 3. Transplacental passage of olomoucine II and purvalanol A from mother to foetus is significantly reduced by active transporters, restricting thereby foetal exposure and providing protection against harmful effects of these xenobiotics. Importantly, we demonstrate that in spite of their considerable structural similarity, the two molecules utilise distinct placental transport systems. These facts should be kept in mind when introducing these prospective anticancer candidates and/or their analogues into the clinical area.

• MeSH
• ATP-Binding Cassette Transporters metabolism   MeSH
• Adenosine Triphosphate chemistry   MeSH
• Biological Transport, Active MeSH
• Rats MeSH
• Maternal Exposure MeSH
• ATP Binding Cassette Transporter, Subfamily B metabolism   MeSH
• Placenta drug effects   metabolism   MeSH
• Rats, Wistar MeSH
• Multidrug Resistance-Associated Proteins metabolism   MeSH
• Purines administration & dosage   pharmacokinetics   MeSH
• Pregnancy, Animal MeSH
• Pregnancy MeSH
• Trophoblasts drug effects   MeSH
• Chromatography, High Pressure Liquid MeSH
• Xenobiotics chemistry   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Pregnancy MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Ritonavir (RIT) is a widely used antiviral drug that acts as an HIV protease inhibitor with emerging potential in anticancer therapies. RIT causes inhibition of P-glycoprotein, which plays an important role in multidrug resistance (MDR) in cancer cells when overexpressed. Moreover, RIT causes mitochondrial dysfunction, leading to decreased ATP production and reduction of caveolin I expression, which can affect cell migration and tumor progression. To increase its direct antitumor activity, decrease severe side effects induced by the use of free RIT and improve its pharmacokinetics, ritonavir 5-methyl-4-oxohexanoate (RTV) was synthesized and conjugated to a tumor-targeted polymer carrier based on a N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer. Here we demonstrated that polymer-bound RTV enhanced the internalization of polymer-RTV conjugates, differing in RTV content from 4 to 15 wt%, in HeLa cancer cells compared with polymer without RTV. The most efficient influx and internalization properties were determined for the polymer conjugate bearing 11 wt% of RTV. This conjugate was internalized by cells using both caveolin- and clathrin-dependent endocytic pathways in contrast to the RTV-free polymer, which was preferentially internalized only by clathrin-mediated endocytosis. Moreover, we found the co-localization of the RTV-conjugate with mitochondria and a significant decrease of ATP production in treated cells. Thus, the impact on mitochondrial mechanism can influence the function of ATP-dependent P-glycoprotein and also the cell viability of MDR cancer cells. Overall, this study demonstrated that the polymer-RTV conjugate is a promising polymer-based nanotherapeutic, suitable for antitumor combination therapy with other anticancer drugs and a potential mitochondrial drug delivery system.

• MeSH
• Adenosine Triphosphate biosynthesis   MeSH
• Drug Resistance, Neoplasm drug effects   MeSH
• Endocytosis drug effects   MeSH
• HeLa Cells MeSH
• Caveolin 1 biosynthesis   genetics   MeSH
• Clathrin pharmacology   MeSH
• Hydrogen-Ion Concentration MeSH
• Humans MeSH
• Methacrylates chemistry   MeSH
• Nanostructures chemistry   MeSH
• ATP Binding Cassette Transporter, Subfamily B, Member 1 drug effects   metabolism   MeSH
• Polymers MeSH
• Antineoplastic Agents administration & dosage   chemistry   MeSH
• Ritonavir administration & dosage   analogs & derivatives   chemistry   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

The effect of alcohols on cell membrane proteins has originally been assumed to be mediated by their primary action on membrane lipid matrix. Many studies carried out later on both animal and yeast cells have revealed that ethanol and other alcohols inhibit the functions of various membrane channels, receptors and solute transport proteins, and a direct interaction of alcohols with these membrane proteins has been proposed. Using our fluorescence diS-C3 (3) diagnostic assay for multidrug-resistance pump inhibitors in a set of isogenic yeast Pdr5p and Snq2p mutants, we found that n-alcohols (from ethanol to hexanol) variously affect the activity of both pumps. Beginning with propanol, these alcohols have an inhibitory effect that increases with increasing length of the alcohol acyl chain. While ethanol does not exert any inhibitory effect at any of the concentration used (up to 3%), hexanol exerts a strong inhibition at 0.1%. The alcohol-induced inhibition of MDR pumps was detected even in cells whose membrane functional and structural integrity were not compromised. This supports a notion that the inhibitory action does not necessarily involve only changes in the lipid matrix of the membrane but may entail a direct interaction of the alcohols with the pump proteins.

• MeSH
• ATP-Binding Cassette Transporters antagonists & inhibitors   genetics   metabolism   MeSH
• Adenosine Triphosphate metabolism   MeSH
• Alcohols pharmacology   MeSH
• Drug Resistance, Fungal genetics   MeSH
• Ions metabolism   MeSH
• Microbial Sensitivity Tests MeSH
• Cell Membrane Permeability drug effects   MeSH
• Saccharomyces cerevisiae Proteins antagonists & inhibitors   genetics   metabolism   MeSH
• Saccharomyces cerevisiae drug effects   genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Adenosine triphosphate-binding cassette proteins constitute a large family of active transporters through extracellular and intracellular membranes. Increased drug efflux based on adenosine triphosphate-binding cassette protein activity is related to the development of cancer cell chemoresistance. Several articles have focused on adenosine triphosphate-binding cassette gene expression profiles (signatures), based on the expression of all 49 human adenosine triphosphate-binding cassette genes, in individual tumor types and reported connections to established clinicopathological features. The aim of this study was to test our theory about the existence of adenosine triphosphate-binding cassette gene expression profiles common to multiple types of tumors, which may modify tumor progression and provide clinically relevant information. Such general adenosine triphosphate-binding cassette profiles could constitute a new attribute of carcinogenesis. Our combined cohort consisted of tissues from 151 cancer patients-breast, colorectal, and pancreatic carcinomas. Standard protocols for RNA isolation and quantitative real-time polymerase chain reaction were followed. Gene expression data from individual tumor types as well as a merged tumor dataset were analyzed by bioinformatics tools. Several general adenosine triphosphate-binding cassette profiles, with differences in gene functions, were established and shown to have significant relations to clinicopathological features such as tumor size, histological grade, or clinical stage. Genes ABCC7, A3, A8, A12, and C8 prevailed among the most upregulated or downregulated ones. In conclusion, the results supported our theory about general adenosine triphosphate-binding cassette gene expression profiles and their importance for cancer on clinical as well as research levels. The presence of ABCC7 (official symbol CFTR) among the genes with key roles in the profiles supports the emerging evidence about its crucial role in various cancers. Graphical abstract.

• MeSH
• ATP-Binding Cassette Transporters biosynthesis   genetics   MeSH
• Carcinogenesis * MeSH
• Colorectal Neoplasms genetics   pathology   MeSH
• Humans MeSH
• Breast Neoplasms genetics   pathology   MeSH
• Pancreatic Neoplasms genetics   pathology   MeSH
• Cystic Fibrosis Transmembrane Conductance Regulator biosynthesis   genetics   MeSH
• Sulfonylurea Receptors biosynthesis   genetics   MeSH
• Gene Expression Regulation, Neoplastic MeSH
• Transcriptome genetics   MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Alzheimer's disease (AD) is a devastating neurological disorder characterized by the pathological accumulation of macromolecular Aβ and tau leading to neuronal death. Drugs approved to treat AD may ameliorate disease symptoms, however, no curative treatment exists. Aβ peptides were discovered to be substrates of adenosine triphosphate-(ATP)-binding cassette (ABC) transporters. Activators of these membrane-bound efflux proteins that promote binding and/or translocation of Aβ could revolutionize AD medicine. The knowledge about ABC transporter activators is very scarce, however, the few molecules that were reported contain substructural features of multitarget (pan-)ABC transporter inhibitors. A cutting-edge strategy to obtain new drug candidates is to explore and potentially exploit the recently proposed multitarget binding site of pan-ABC transporter inhibitors as anchor point for the development of innovative activators to promote Aβ clearance from the brain. Molecular associations between functional bioactivities and physicochemical properties of small-molecules are key to understand these processes. This study provides an analysis of a recently reported unique multitarget dataset for the correlation between multitarget bioactivity and physicochemistry. Six novel pan-ABC transporter inhibitors were validated containing substructural features of ABC transporter activators, which underpins the relevance of the multitarget binding site for the targeted development of novel AD diagnostics and therapeutics.

• MeSH
• ATP Binding Cassette Transporter, Subfamily G, Member 2 metabolism   MeSH
• ATP-Binding Cassette Transporters metabolism   MeSH
• Alzheimer Disease * drug therapy   metabolism   MeSH
• Biological Transport MeSH
• Chemical Phenomena MeSH
• Humans MeSH
• Brain metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Inherited disorders of surfactant metabolism are manifested in neonatal period as a severe respiratory failure not responding to exogenous surfactant administration. We illustrate the case of a term newborn with respiratory failure because of compound heterozygous mutation in adenosine triphosphate-binding cassette transporter A3 (ABCA3)-in exon 24 M1227R and in exon 29 Ins1510fs/ter1519. These mutations of ABCA3 have not been described yet and expand the group of lethal ABCA3 variants.

• MeSH
• ATP-Binding Cassette Transporters genetics   MeSH
• Fatal Outcome MeSH
• Genetic Heterogeneity MeSH
• Genetic Variation MeSH
• Humans MeSH
• DNA Mutational Analysis MeSH
• Infant, Newborn MeSH
• Term Birth MeSH
• Respiratory Insufficiency genetics   therapy   MeSH
• High-Frequency Ventilation MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Infant, Newborn MeSH
• Publication type
• Journal Article MeSH
• Case Reports MeSH
• Research Support, Non-U.S. Gov't MeSH

Chalcones, potential anticancer agents, have shown promise in the suppression of multidrug resistance due to the inhibition of drug efflux driven by certain adenosine triphosphate (ATP)-binding cassette (ABC) transporters. The gene and protein expression of chosen ABC transporters (multidrug resistance protein 1, ABCB1; multidrug resistance-associated protein 1, ABCC1; and breast cancer resistance protein, ABCG2) in human colorectal cancer cells (COLO 205 and COLO 320, which overexpress active ABCB1) was mainly studied in this work under the influence of a novel synthetic acridine-based chalcone, 1C. While gene expression dropped just at 24 h, compound 1C selectively suppressed colorectal cancer cell growth and greatly lowered ABCB1 protein levels in COLO 320 cells at 24, 48, and 72 h. It also reduced ABCC1 protein levels after 48 h. Molecular docking and ATPase tests show that 1C probably acts as an allosteric modulator of ABCB1. It also lowered galectin-1 (GAL1) expression in COLO 205 cells at 24 h. Functional tests on COLO cells revealed ABCB1 and ABCC1/2 to be major contributors to multidrug resistance in both. Overall, 1C transiently lowered GAL1 in COLO 205 while affecting important functional ABC transporters, mostly ABCB1 and to a lesser extent ABCC1 in COLO 320 cells. COLO 320's absence of GAL1 expression points to a possible yet unknown interaction between GAL1 and ABCB1.

• MeSH
• ATP Binding Cassette Transporter, Subfamily G, Member 2 metabolism   MeSH
• ATP-Binding Cassette Transporters * metabolism   chemistry   genetics   MeSH
• Acridines * chemistry   pharmacology   MeSH
• Chalcone * pharmacology   chemistry   MeSH
• Chalcones * pharmacology   chemistry   MeSH
• Drug Resistance, Neoplasm drug effects   MeSH
• Colorectal Neoplasms metabolism   drug therapy   MeSH
• Humans MeSH
• Cell Line, Tumor MeSH
• ATP Binding Cassette Transporter, Subfamily B metabolism   genetics   MeSH
• Cell Proliferation drug effects   MeSH
• Multidrug Resistance-Associated Protein 2 MeSH
• Multidrug Resistance-Associated Proteins metabolism   genetics   MeSH
• Antineoplastic Agents * pharmacology   chemistry   MeSH
• Gene Expression Regulation, Neoplastic drug effects   MeSH
• Molecular Docking Simulation MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Multidrug resistance (MDR) is a major challenge for the 21th century in both cancer chemotherapy and antibiotic treatment of bacterial infections. Efflux pumps and transport proteins play an important role in MDR. Compounds displaying inhibitory activity toward these proteins are prospective for adjuvant treatment of such conditions. Natural low-cost and nontoxic flavonoids, thanks to their vast structural diversity, offer a great pool of lead structures with broad possibility of chemical derivatizations. Various flavonoids were found to reverse both antineoplastic and bacterial multidrug resistance by inhibiting Adenosine triphosphate Binding Cassette (ABC)-transporters (human P-glycoprotein, multidrug resistance-associated protein MRP-1, breast cancer resistance protein, and bacterial ABC transporters), as well as other bacterial drug efflux pumps: major facilitator superfamily (MFS), multidrug and toxic compound extrusion (MATE), small multidrug resistance (SMR) and resistance-nodulation-cell-division (RND) transporters, and glucose transporters. Flavonoids and particularly flavonolignans are therefore highly prospective compounds for defying multidrug resistance.

• MeSH
• ATP-Binding Cassette Transporters antagonists & inhibitors   genetics   metabolism   MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacteria genetics   metabolism   MeSH
• Bacterial Infections drug therapy   microbiology   MeSH
• Drug Resistance, Bacterial * MeSH
• Bacterial Proteins antagonists & inhibitors   genetics   metabolism   MeSH
• Drug Resistance, Neoplasm * MeSH
• Flavonoids administration & dosage   MeSH
• Flavonolignans administration & dosage   MeSH
• Humans MeSH
• Neoplasms drug therapy   genetics   metabolism   MeSH
• Antineoplastic Agents therapeutic use   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH