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The Journal of Pharmacology and... Dec 2023Achieving adequate exposure of the free therapeutic agent at the target is a critical determinant of efficacious chemotherapy. With this in mind, a major challenge in...
Achieving adequate exposure of the free therapeutic agent at the target is a critical determinant of efficacious chemotherapy. With this in mind, a major challenge in developing therapies for central nervous system (CNS) tumors is to overcome barriers to delivery, including the blood-brain barrier (BBB). Panobinostat is a nonselective pan-histone deacetylase inhibitor that is being tested in preclinical and clinical studies, including for the treatment of pediatric medulloblastoma, which has a propensity for leptomeningeal spread and diffuse midline glioma, which can infiltrate into supratentorial brain regions. In this study, we examined the rate, extent, and spatial heterogeneity of panobinostat CNS distribution in mice. Transporter-deficient mouse studies show that panobinostat is a dual substrate of P-glycoprotein (P-gp) and breast cancer resistant protein (Bcrp), which are major efflux transporters expressed at the BBB. The CNS delivery of panobinostat was moderately limited by P-gp and Bcrp, and the unbound tissue-to-plasma partition coefficient of panobinostat was 0.32 and 0.21 in the brain and spinal cord in wild-type mice. In addition, following intravenous administration, panobinostat demonstrated heterogeneous distribution among brain regions, indicating that its efficacy would be influenced by tumor location or the presence and extent of leptomeningeal spread. Simulation using a compartmental BBB model suggests inadequate exposure of free panobinostat in the brain following a recommended oral dosing regimen in patients. Therefore, alternative approaches to CNS delivery may be necessary to have adequate exposure of free panobinostat for the treatment of a broad range of pediatric brain tumors. SIGNIFICANCE STATEMENT: This study shows that the central nervous system (CNS) penetration of panobinostat is limited by P-gp and Bcrp, and its efficacy may be limited by inadequate distribution to the tumor. Panobinostat has heterogeneous distribution into various brain regions, indicating that its efficacy might depend on the anatomical location of the tumors. These distributional parameters in the mouse CNS can inform both preclinical and clinical trial study design and may guide treatment for these devastating brain tumors in children.
Topics: Child; Humans; Animals; Mice; Panobinostat; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Neoplasm Proteins; Central Nervous System; Brain; Blood-Brain Barrier; Brain Neoplasms; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Membrane Transport Proteins
PubMed: 37827699
DOI: 10.1124/jpet.123.001826 -
Molecules (Basel, Switzerland) Nov 2023P-glycoprotein (P-gp) is a crucial membrane transporter situated on the cell's apical surface, being responsible for eliminating xenobiotics and endobiotics. P-gp... (Review)
Review
P-glycoprotein (P-gp) is a crucial membrane transporter situated on the cell's apical surface, being responsible for eliminating xenobiotics and endobiotics. P-gp modulators are compounds that can directly or indirectly affect this protein, leading to changes in its expression and function. These modulators can act as inhibitors, inducers, or activators, potentially causing drug-drug interactions (DDIs). This comprehensive review explores diverse models and techniques used to assess drug-induced P-gp modulation. We cover several approaches, including , , , and methods, with their respective strengths and limitations. Additionally, we explore the therapeutic implications of DDIs involving P-gp, with a special focus on the renal and intestinal elimination of P-gp substrates. This involves enhancing the removal of toxic substances from proximal tubular epithelial cells into the urine or increasing the transport of compounds from enterocytes into the intestinal lumen, thereby facilitating their excretion in the feces. A better understanding of these interactions, and of the distinct techniques applied for their study, will be of utmost importance for optimizing drug therapy, consequently minimizing drug-induced adverse and toxic effects.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Membrane Transport Proteins; ATP Binding Cassette Transporter, Subfamily B; Kidney; Drug Interactions
PubMed: 38005253
DOI: 10.3390/molecules28227532 -
European Journal of Medicinal Chemistry Dec 2023The compact and versatile oxetane motifs have gained significant attention in drug discovery and medicinal chemistry campaigns. This review presents an overview of the... (Review)
Review
The compact and versatile oxetane motifs have gained significant attention in drug discovery and medicinal chemistry campaigns. This review presents an overview of the diverse applications of oxetanes in clinical and preclinical drug candidates targeting various human diseases, including cancer, viral infections, autoimmune disorders, neurodegenerative conditions, metabolic disorders, and others. Special attention is given to biologically active oxetane-containing compounds and their disease-related targets, such as kinases, epigenetic and non-epigenetic enzymes, and receptors. The review also details the effect of the oxetane motif on important properties, including aqueous solubility, lipophilicity, pKa, P-glycoprotein (P-gp) efflux, metabolic stability, conformational preferences, toxicity profiles (e.g., cytochrome P450 (CYP) suppression and human ether-a-go-go related gene (hERG) inhibition), pharmacokinetic (PK) properties, potency, and target selectivity. We anticipate that this work will provide valuable insights that can drive future discoveries of novel bioactive oxetane-containing small molecules, enabling their effective application in combating a wide range of human diseases.
Topics: Humans; Chemistry, Pharmaceutical; Drug Discovery; Ethers, Cyclic; Molecular Conformation
PubMed: 37713805
DOI: 10.1016/j.ejmech.2023.115802 -
Biopharmaceutics & Drug Disposition Oct 2023α-Defensin 5 is known to be secreted by Paneth cells in the small intestine and plays an important role in eliminating pathogenic microorganisms. It has been reported...
α-Defensin 5 is known to be secreted by Paneth cells in the small intestine and plays an important role in eliminating pathogenic microorganisms. It has been reported that a decrease in α-defensin 5 level in the human small intestine is a risk of inflammatory bowel disease (IBD). Furthermore, P-glycoprotein (P-gp), a member of the ATP-binding cassette transporter superfamily, encoded by the ABCB1/MDR1 gene, plays an important role in the front line of host defense by protecting the gastrointestinal barrier from xenobiotic accumulation and may contribute to the development and persistence of IBD. Therefore, we examined the relationship between α-defensin 5 and the expression and function of P-gp using a human gastrointestinal model cell line (Caco-2). We found that MDR1 mRNA and P-gp protein level were increased in Caco-2 cells as well as α-defensin 5 secretion corresponded with the duration of cell culture. Exposure to α-defensin 5 peptide and recombinant tumor necrosis factor-α (TNF-α) significantly increased the expression and function P-gp. The mRNA levels of interleukin (IL)-8, IL-6, TNF-α, IL-1β, and IL-2 were also increased following exposure to TNF-α, similar to α-defensin 5 treatment. These results suggest that α-defensin 5 regulates P-gp expression and function by increasing TNF-α expression in Caco-2 cells.
Topics: Humans; ATP Binding Cassette Transporter, Subfamily B, Member 1; Caco-2 Cells; alpha-Defensins; Tumor Necrosis Factor-alpha; ATP Binding Cassette Transporter, Subfamily B; Inflammatory Bowel Diseases; RNA, Messenger
PubMed: 37277970
DOI: 10.1002/bdd.2367 -
Journal of Personalized Medicine Jul 2023Interethnic and interindividual variability in in vivo cytochrome P450 (CYP450)-dependent metabolism and altered drug absorption via expressed transport channels such as... (Review)
Review
Interethnic and interindividual variability in in vivo cytochrome P450 (CYP450)-dependent metabolism and altered drug absorption via expressed transport channels such as P-glycoprotein (P-gp) contribute to the adverse drug reactions, drug-drug interaction and therapeutic failure seen in clinical practice. A cost-effective phenotyping approach could be advantageous in providing real-time information on in vivo phenotypes to assist clinicians with individualized drug therapy, especially in resource-constrained countries such as South Africa. A number of phenotyping cocktails have been developed and the aim of this study was to critically assess the feasibility of their use in a South African context. A literature search on library databases (including AccessMedicine, BMJ, ClinicalKey, MEDLINE (Ovid), PubMed, Scopus and TOXLINE) was limited to in vivo cocktails used in the human population to phenotype phase I metabolism and/or P-gp transport. The study found that the implementation of phenotyping in clinical practice is currently limited by multiple administration routes, the varying availability of probe drugs, therapeutic doses eliciting side effects, the interaction between probe drugs and extensive sampling procedures. Analytical challenges include complicated sample workup or extraction assays and impractical analytical procedures with low detection limits, analyte sensitivity and specificity. It was concluded that a single time point, non-invasive capillary sampling, combined with a low-dose probe drug cocktail, to simultaneously quantify in vivo drug and metabolite concentrations, would enhance the feasibility and cost-effectiveness of routine phenotyping in clinical practice; however, future research is needed to establish whether the quantitative bioanalysis of drugs in a capillary whole-blood matrix correlates with that of the standard plasma/serum matrixes used as a reference in the current clinical environment.
PubMed: 37511712
DOI: 10.3390/jpm13071098 -
Journal of Pharmaceutical Sciences Jan 2024This report focuses on pharmacokinetic drug-endogenous substrate interactions (DEIs). We hypothesized that P-glycoprotein (P-gp)-mediated DEI might affect androgen...
This report focuses on pharmacokinetic drug-endogenous substrate interactions (DEIs). We hypothesized that P-glycoprotein (P-gp)-mediated DEI might affect androgen kinetics, especially its blood-brain barrier (BBB) permeability. The intracellular accumulation of the endogenous substrates of P-gp, testosterone (TES) and androstenedione (ADO) was increased by several tested drugs in uptake studies using P-gp overexpressing cells, indicating that these drugs inhibit P-gp-mediated efflux of TES of ADO from the cells. In a transport study using rat BBB kit, we found that the BBB limited the penetration of TES and ADO into the central nervous system. In addition, tested drugs that cause DEI were found to increase BBB permeability of TES and ADO via P-gp inhibition. In short, this study provides new findings regarding the possibility that DEI may affect the kinetics of endogenous substrates of P-gp.
Topics: Rats; Animals; Blood-Brain Barrier; Androgens; Biological Transport; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Permeability; Testosterone
PubMed: 37898165
DOI: 10.1016/j.xphs.2023.10.034 -
Anticancer Research Mar 2024Evidence supports that use of aripiprazole sensitizes drug-resistant oral cancer cells. The aim of the study was to investigate whether aripiprazole can achieve...
BACKGROUND/AIM
Evidence supports that use of aripiprazole sensitizes drug-resistant oral cancer cells. The aim of the study was to investigate whether aripiprazole can achieve sensitization of highly drug-resistant breast cancer cells, as well as identify its relevant mechanisms of action.
MATERIALS AND METHODS
MCF-7/ADR, KB, and KBV20C breast cancer cells were treated with aripiprazole, vincristine (VIC), vinorelbine, vinblastine and their combination. Cell viability assay, annexin V analyses, cellular morphology and density observation with a microscope, western-blotting, fluorescence-activated cell sorting (FACS), and analysis for P-gp inhibitory activity were performed to investigate the drugs' mechanism of action.
RESULTS
We found that high drug resistance in MCF-7/ADR cells results from high P-gp inhibitory activity via overexpression of P-gp. Aripiprazole reduced cell viability, increased G arrest, and upregulated apoptosis when used as a co-treatment with VIC. Furthermore, we demonstrated that co-treatment with vinorelbine and vinblastine increased the sensitization of MCF-7/ADR breast cancer cells to aripiprazole. We confirmed that VIC-aripiprazole combination has much higher sensitization effects than either VIC-thioridazine or VIC-trifluoperazine co-treatment in MCF-7/ADR cells, since the previously known bipolar drugs (thioridazine and trifluoperazine) has lower P-gp inhibitory activity. However, aripiprazole-induced sensitization was not observed in VIC-treated MDA-MB-231 breast cancer cells suggesting that combination therapy with aripiprazole is specific for P-gp-overexpressing drug-resistant breast cancer cells.
CONCLUSION
Co-treatment with low doses of aripiprazole sensitized MCF-7/ADR cells to VIC. Combination therapy with aripiprazole may be a valuable tool for delaying or reducing cancer recurrence by targeting P-gp-overexpressing drug-resistant breast cancer cells.
Topics: Humans; Female; Vincristine; ATP Binding Cassette Transporter, Subfamily B, Member 1; Aripiprazole; Vinorelbine; Breast Neoplasms; Vinblastine; MCF-7 Cells; Thioridazine; Trifluoperazine; Drug Resistance, Neoplasm; Cell Line, Tumor; ATP Binding Cassette Transporter, Subfamily B; Doxorubicin
PubMed: 38423668
DOI: 10.21873/anticanres.16900 -
Heliyon Sep 2023P-glycoprotein (P-gp) is known as the "" because it contributes to tumor resistance to several different classes of anticancer drugs. The effectiveness of such polymers...
P-glycoprotein (P-gp) is known as the "" because it contributes to tumor resistance to several different classes of anticancer drugs. The effectiveness of such polymers in treating cancer and delivering drugs has been shown in a wide range of and experiments. The primary objective of the present study was to investigate the inhibitory effects of several naturally occurring polymers on P-gp efflux, as it is known that P-gp inhibition can impede the elimination of medications. The objective of our study is to identify polymers that possess the potential to inhibit P-gp, a protein involved in drug resistance, with the aim of enhancing the effectiveness of anticancer drug formulations. The ADMET profile of all the selected polymers (Agarose, Alginate, Carrageenan, Cyclodextrin, Dextran, Hyaluronic acid, and Polysialic acid) has been studied, and binding affinities were investigated through a computational approach using the recently released crystal structure of P-gp with PDB ID: 7O9W. The advanced computational study was also done with the help of molecular dynamics simulation. The aim of the present study is to overcome MDR resulting from the activity of P-gp by using such polymers that can inhibit P-gp when used in formulations. The docking scores of native ligand, Agarose, Alginate, Carrageenan, Chitosan, Cyclodextrin, Dextran, Hyaluronic acid, and Polysialic acid were found to be -10.7, -8.5, -6.6, -8.7, -8.6, -24.5, -6.7, -8.3, and -7.9, respectively. It was observed that, Cyclodextrin possess multiple properties in drug delivery science and here also demonstrated excellent binding affinity. We propose that drug efflux-related MDR may be prevented by the use of Agarose, Carregeenan, Chitosan, Cyclodextrin, Hyaluronic acid, and/or Polysialic acid in the administration of anticancer drugs.
PubMed: 37662819
DOI: 10.1016/j.heliyon.2023.e19454 -
Establishment and Characterization of Multi-Drug Resistant p53-Negative Osteosarcoma SaOS-2 Subline.Diagnostics (Basel, Switzerland) Aug 2023To establish a p53-negative osteosarcoma (OS) SaOS-2 cellular subline exhibiting resistance to specific chemotherapeutic agents, including topoisomerase II inhibitors,...
AIM
To establish a p53-negative osteosarcoma (OS) SaOS-2 cellular subline exhibiting resistance to specific chemotherapeutic agents, including topoisomerase II inhibitors, taxanes, and vinca alkaloids.
METHODS
The OS subline exhibiting resistance to the chemotherapeutic agents indicated above was generated by the stepwise treatment of the parental SaOS-2 cell line with increasing concentrations of doxorubicin (Dox) for 5 months. Half-inhibitory concentrations (IC) for Dox, vinblastine (Vin), and paclitaxel (PTX) were calculated by a colorimetric MTS-based assay. Crystal violet staining was used to assess cellular viability, whereas the proliferation capacities of cancer cells were monitored in real-time by the i-Celligence system. Expression of apoptotic markers (e.g., cleaved PARP and caspase-3), DNA repair proteins (e.g., ATM, DNA-PK, Nbs1, Rad51, MSH2, etc.), and certain ABC transporters (P-glycoprotein, MRP1, ABCG2, etc.) was assessed by western blotting and real-time PCR. Flow cytometry was used to examine the fluorescence intensity of Dox and ABC-transporter substrates (e.g., Calcein AM and CMFDA) and to assess their excretion to define the activity of specific ABC-transporters. To confirm OS resistance to Dox in vivo, xenograft experiments were performed.
RESULTS
An OS subline generated by a stepwise treatment of the parental SaOS-2 cell line with increasing concentrations of Dox resulted in an increase in the IC for Dox, Vin, and PTX (~6-, 4-, and 30-fold, respectively). The acquisition of chemoresistance in vitro was also evidenced by the lack of apoptotic markers (e.g., cleaved PARP and caspase-3) in resistant OS cells treated with the chemotherapeutic agents indicated above. The development of the multidrug resistance (MDR) phenotype in this OS subline was due to the overexpression of ABCB1 (i.e., P-glycoprotein) and ABCC1 (i.e., multidrug resistance protein-1, MRP-1), which was evidenced on both mRNA and protein levels. Due to increased expression of MDR-related proteins, resistant OS exhibited an excessive efflux of Dox. Moreover, decreased accumulation of calcein AM, a well-known fluorescent substrate for both ABCB1 and ABCC1, was observed for resistant OS cells compared to their parental SaOS-2 cell line. Importantly, tariquidar and cyclosporin, well-known ABC inhibitors, retained the intensity of Dox-induced fluorescence in resistant SAOS-2 cells. Furthermore, in addition to the increased efflux of the chemotherapeutic agents from Dox-resistant OS cells, we found higher expression of several DNA repair proteins (e.g., Rad51 recombinase, Mre11, and Nbs1, activated forms of ATM, DNA-PK, Chk1, and Chk2, etc.), contributing to the chemoresistance due to the excessive DNA repair. Lastly, the in vivo study indicated that Dox has no impact on the SaOS-2 Dox-R xenograft tumor growth in a nude mouse model.
CONCLUSIONS
An acquired resistance of OS to the chemotherapeutic agents might be due to the several mechanisms undergoing simultaneously on the single-cell level. This reveals the complexity of the mechanisms involved in the secondary resistance of OS to chemotherapies.
PubMed: 37627905
DOI: 10.3390/diagnostics13162646 -
Carbohydrate Polymers Mar 2024Overcoming P-glycoprotein (P-gp)-mediated efflux poses a significant challenge for the pharmaceutical industry. This study investigates the potential of thiolated...
Overcoming P-glycoprotein (P-gp)-mediated efflux poses a significant challenge for the pharmaceutical industry. This study investigates the potential of thiolated β-cyclodextrins (β-CD-SHs) as inhibitors of P-gp-mediated efflux in Caco-2 cells. Through a series of transport assays, intracellular accumulation, and efflux of the P-gp substrates Rhodamine 123 (Rh123) and Calcein-AM with and without co-administration of β-CD-SHs were assessed. The results revealed that the cellular uptake of Rh123 and Calcein-AM were enhanced up to 7- and 3-fold, compared to the control, respectively. In efflux studies an up to 2.5-fold reduction of the Rh123 efflux was reached compared the control, indicating a substantial decrease of Rh123 efflux by β-CD-SHs. Furthermore, it was observed that β-CD-SHs led to a decrease in the reactivity of fluorescence-labeled anti-P-gp, suggesting additional effects on the conformation of P-gp. Overall, this study demonstrates the potential of β-CD-SHs as effective modulator of P-gp-mediated drug efflux in Caco-2 cells.
Topics: Humans; ATP Binding Cassette Transporter, Subfamily B, Member 1; Caco-2 Cells; Cyclodextrins; Rhodamine 123
PubMed: 38171673
DOI: 10.1016/j.carbpol.2023.121648