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1.
Blood ; 142(23): 1960-1971, 2023 12 07.
Article in English | MEDLINE | ID: mdl-37647654

ABSTRACT

Sorafenib maintenance improves outcomes after hematopoietic cell transplant (HCT) for patients with FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) acute myeloid leukemia (AML). Although promising outcomes have been reported for sorafenib plus intensive chemotherapy, randomized data are limited. This placebo-controlled, phase 2 study (ACTRN12611001112954) randomized 102 patients (aged 18-65 years) 2:1 to sorafenib vs placebo (days 4-10) combined with intensive induction: idarubicin 12 mg/m2 on days 1 to 3 plus either cytarabine 1.5 g/m2 twice daily on days 1, 3, 5, and 7 (18-55 years) or 100 mg/m2 on days 1 to 7 (56-65 years), followed by consolidation and maintenance therapy for 12 months (post-HCT excluded) in newly diagnosed patients with FLT3-ITD AML. Four patients were excluded in a modified intention-to-treat final analysis (3 not commencing therapy and 1 was FLT3-ITD negative). Rates of complete remission (CR)/CR with incomplete hematologic recovery were high in both arms (sorafenib, 78%/9%; placebo, 70%/24%). With 49.1-months median follow-up, the primary end point of event-free survival (EFS) was not improved by sorafenib (2-year EFS 47.9% vs 45.4%; hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.51-1.51; P = .61). Two-year overall survival (OS) was 67% in the sorafenib arm and 58% in the placebo arm (HR, 0.76; 95% CI, 0.42-1.39). For patients who received HCT in first remission, the 2-year OS rates were 84% and 67% in the sorafenib and placebo arms, respectively (HR, 0.45; 95% CI, 0.18-1.12; P = .08). In exploratory analyses, FLT3-ITD measurable residual disease (MRD) negative status (<0.001%) after induction was associated with improved 2-year OS (83% vs 60%; HR, 0.4; 95% CI, 0.17-0.93; P = .028). In conclusion, routine use of pretransplant sorafenib plus chemotherapy in unselected patients with FLT3-ITD AML is not supported by this study.


Subject(s)
Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute , Humans , Sorafenib , fms-Like Tyrosine Kinase 3/genetics , Retrospective Studies , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics
2.
Chemistry ; 30(46): e202400931, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-38838073

ABSTRACT

Mitochondrial uncoupling by small molecule protonophores is a promising strategy for developing novel anticancer agents. Recently, aryl urea substituted fatty acids (aryl ureas) were identified as a new class of protonophoric anticancer agents. To mediate proton transport these molecules self-assemble into membrane-permeable anionic dimers in which intermolecular hydrogen bonds between the carboxylate and aryl-urea anion receptor delocalise the negative charge across the aromatic π-system. In this work, we extend the aromatic π-system by introducing a second phenyl substituent to the aryl urea scaffold and compare the proton transport mechanisms and mitochondrial uncoupling actions of these compounds to their monoaryl analogues. It was found that incorporation of meta-linked phenyl substituents into the aryl urea scaffold enhanced proton transport in vesicles and demonstrated superior capacity to depolarise mitochondria, inhibit ATP production and reduce the viability of MDA-MB-231 breast cancer cells. In contrast, diphenyl ureas linked through a 1,4-distribution across the phenyl ring displayed diminished proton transport activity, despite both diphenyl urea isomers possessing similar binding affinities for carboxylates. Mechanistic studies suggest that inclusion of a second aryl ring changes the proton transport mechanism, presumably due to steric factors that impose higher energy penalties for dimer formation.


Subject(s)
Fatty Acids , Mitochondria , Protons , Urea , Humans , Fatty Acids/chemistry , Fatty Acids/metabolism , Mitochondria/metabolism , Urea/chemistry , Urea/analogs & derivatives , Urea/pharmacology , Cell Line, Tumor , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/metabolism , Uncoupling Agents/pharmacology , Uncoupling Agents/chemistry , Ion Transport , Anions/chemistry , Anions/metabolism , Adenosine Triphosphate/metabolism , Adenosine Triphosphate/chemistry
3.
Org Biomol Chem ; 22(24): 4868-4876, 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38764358

ABSTRACT

The N,N'-dimethylation of a diphenylsquaramide induces a conformational change in the orientation of the phenyl rings. This has been exploited to create a series of bis-urea, -thiourea and -squaramide anionophores. The compounds were shown to bind to Cl- using proton NMR titration techniques and to transport H+/Cl- through the lipid bilayers, whereas a non-methylated analogue displayed limited transport activity. Despite their potency in transport studies, the series had a negligible impact on cancer cell viability.

4.
Int J Mol Sci ; 25(12)2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38928494

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC)'s resistance to therapies is mainly attributed to pancreatic cancer stem cells (PCSCs). Mitochondria-impairing agents can be used to hamper PCSC propagation and reduce PDAC progression. Therefore, to develop an efficient vector for delivering drugs to the mitochondria, we synthesized tris(3,5-dimethylphenyl)phosphonium-conjugated palmitic acid. Triphenylphosphonium (TPP) is a lipophilic cationic moiety that promotes the accumulation of conjugated agents in the mitochondrion. Palmitic acid (PA), the most common saturated fatty acid, has pro-apoptotic activity in different types of cancer cells. TPP-PA was prepared by the reaction of 16-bromopalmitic acid with TPP, and its structure was characterized by 1H and 13C NMR and HRMS. We compared the proteomes of TPP-PA-treated and untreated PDAC cells and PCSCs, identifying dysregulated proteins and pathways. Furthermore, assessments of mitochondrial membrane potential, intracellular ROS, cardiolipin content and lipid peroxidation, ER stress, and autophagy markers provided information on the mechanism of action of TPP-PA. The findings showed that TPP-PA reduces PDAC cell proliferation through mitochondrial disruption that leads to increased ROS, activation of ER stress, and autophagy. Hence, TPP-PA might offer a new approach for eliminating both the primary population of cancer cells and PCSCs, which highlights the promise of TPP-derived compounds as anticancer agents for PDAC.


Subject(s)
Mitochondria , Organophosphorus Compounds , Palmitic Acid , Pancreatic Neoplasms , Proteomics , Humans , Mitochondria/metabolism , Mitochondria/drug effects , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Palmitic Acid/pharmacology , Palmitic Acid/chemistry , Organophosphorus Compounds/pharmacology , Organophosphorus Compounds/chemistry , Proteomics/methods , Cell Line, Tumor , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/pathology , Cell Proliferation/drug effects , Membrane Potential, Mitochondrial/drug effects , Reactive Oxygen Species/metabolism , Apoptosis/drug effects , Proteome/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Autophagy/drug effects
5.
Molecules ; 29(7)2024 Mar 28.
Article in English | MEDLINE | ID: mdl-38611800

ABSTRACT

4-Chloroisocoumarin compounds have broad inhibitory properties against serine proteases. Here, we show that selected 3-alkoxy-4-chloroisocoumarins preferentially inhibit the activity of the conserved serine protease High-temperature requirement A of Chlamydia trachomatis. The synthesis of a new series of isocoumarin-based scaffolds has been developed, and their anti-chlamydial properties were investigated. The structure of the alkoxy substituent was found to influence the potency of the compounds against High-temperature requirement A, and modifications to the C-7 position of the 3-alkoxy-4-chloroisocoumarin structure attenuate anti-chlamydial properties.


Subject(s)
Alcohols , Chlamydia trachomatis , Protease Inhibitors , Protease Inhibitors/pharmacology , Enzyme Therapy , Isocoumarins , Serine Endopeptidases , Serine Proteases
6.
Molecules ; 29(17)2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39275060

ABSTRACT

The accumulation of iron in dopaminergic neurons can cause oxidative stress and dopaminergic neuron degeneration. Iron chelation therapy may reduce dopaminergic neurodegeneration, but chelators should be targeted towards dopaminergic cells. In this work, two series of compounds based on 8-hydroxyquinoline and deferiprone, iron chelators that have amphetamine-like structures, have been designed, synthesized and characterized. Each of these compounds chelated iron ions in aqueous solution. The hydroxyquinoline-based compounds exhibited stronger iron-binding constants than those of the deferiprone derivatives. The hydroxyquinoline-based compounds also exhibited greater free radical scavenging activities compared to the deferiprone derivatives. Molecular dynamics simulations showed that the hydroxyquinoline-based compounds generally bound well within human dopamine transporter cavities. Thus, these compounds are excellent candidates for future exploration as drugs against diseases that are affected by iron-induced dopaminergic neuron damage, such as Parkinson's disease.


Subject(s)
Clioquinol , Deferiprone , Iron Chelating Agents , Iron , Deferiprone/pharmacology , Deferiprone/chemistry , Iron Chelating Agents/pharmacology , Iron Chelating Agents/chemistry , Humans , Iron/chemistry , Iron/metabolism , Clioquinol/pharmacology , Clioquinol/chemistry , Molecular Dynamics Simulation , Dopamine Plasma Membrane Transport Proteins/metabolism , Free Radical Scavengers/pharmacology , Free Radical Scavengers/chemistry , Molecular Structure , Amphetamine/chemistry , Amphetamine/pharmacology
7.
J Biol Chem ; 296: 100282, 2021.
Article in English | MEDLINE | ID: mdl-33450225

ABSTRACT

The role of lipids in modulating membrane protein function is an emerging and rapidly growing area of research. The rational design of lipids that target membrane proteins for the treatment of pathological conditions is a novel extension in this field and provides a step forward in our understanding of membrane transporters. Bioactive lipids show considerable promise as analgesics for the treatment of chronic pain and bind to a high-affinity allosteric-binding site on the human glycine transporter 2 (GlyT2 or SLC6A5). Here, we use a combination of medicinal chemistry, electrophysiology, and computational modeling to develop a rational structure-activity relationship for lipid inhibitors and demonstrate the key role of the lipid tail interactions for GlyT2 inhibition. Specifically, we examine how lipid inhibitor head group stereochemistry, tail length, and double-bond position promote enhanced inhibition. Overall, the l-stereoisomer is generally a better inhibitor than the d-stereoisomer, longer tail length correlates with greater potency, and the position of the double bond influences the activity of the inhibitor. We propose that the binding of the lipid inhibitor deep into the allosteric-binding pocket is critical for inhibition. Furthermore, this provides insight into the mechanism of inhibition of GlyT2 and highlights how lipids can modulate the activity of membrane proteins by binding to cavities between helices. The principles identified in this work have broader implications for the development of a larger class of compounds that could target SLC6 transporters for disease treatment.


Subject(s)
Analgesics/pharmacology , Chronic Pain/drug therapy , Glycine Plasma Membrane Transport Proteins/genetics , Lipids/chemistry , Allosteric Regulation/drug effects , Animals , Binding Sites/drug effects , Biophysical Phenomena , Chronic Pain/genetics , Glycine Plasma Membrane Transport Proteins/antagonists & inhibitors , Glycine Plasma Membrane Transport Proteins/chemistry , Humans , Lipids/antagonists & inhibitors , Membrane Proteins/chemistry , Membrane Proteins/genetics , Membrane Proteins/ultrastructure , Xenopus laevis
8.
J Pharmacol Exp Ther ; 382(3): 246-255, 2022 09.
Article in English | MEDLINE | ID: mdl-35779948

ABSTRACT

Aberrations in spinal glycinergic signaling are a feature of pain chronification. Normalizing these changes by inhibiting glycine transporter (GlyT)-2 is a promising treatment strategy. However, existing GlyT2 inhibitors (e.g., ORG25543) are limited by narrow therapeutic windows and severe dose-limiting side effects, such as convulsions, and are therefore poor candidates for clinical development. Here, intraperitoneally administered oleoyl-D-lysine, a lipid-based GlyT2 inhibitor, was characterized in mouse models of acute (hot plate), inflammatory (complete Freund's adjuvant), and chronic neuropathic (chronic constriction injury) pain. Side effects were also assessed on a numerical rating score, convulsions score, for motor incoordination (rotarod), and for respiratory depression (whole body plethysmography). Oleoyl-D-lysine produced near complete antiallodynia for chronic neuropathic pain, but no antiallodynia/analgesia in inflammatory or acute pain. No side effects were seen at the peak analgesic dose, 30 mg/kg. Mild side effects were observed at the highest dose, 100 mg/kg, on the numerical rating score, but no convulsions. These results contrasted markedly with ORG25543, which reached less than 50% reduction in allodynia score only at the lethal/near-lethal dose of 50 mg/kg. At this dose, ORG25543 caused maximal side effects on the numerical rating score and severe convulsions. Oleoyl-D-lysine (30 mg/kg) did not cause any respiratory depression, a problematic side effect of opiates. These results show the safe and effective reversal of neuropathic pain in mice by oleoyl-D-lysine and provide evidence for a distinct role of glycine in chronic pain over acute or short-term pain conditions. SIGNIFICANCE STATEMENT: Partially inhibiting glycine transporter (GlyT)-2 can alleviate chronic pain by restoring lost glycinergic function. Novel lipid-based GlyT2 inhibitor ol-D-lys is safe and effective in alleviating neuropathic pain, but not inflammatory or acute pain. Clinical application of GlyT2 inhibitors may be better suited to chronic neuropathic pain over other pain aetiologies.


Subject(s)
Acute Pain , Chronic Pain , Neuralgia , Respiratory Insufficiency , Animals , Disease Models, Animal , Glycine Plasma Membrane Transport Proteins , Hyperalgesia/drug therapy , Lipids , Lysine/pharmacology , Lysine/therapeutic use , Male , Mice , Neuralgia/drug therapy , Respiratory Insufficiency/chemically induced , Respiratory Insufficiency/drug therapy
9.
Org Biomol Chem ; 21(1): 132-139, 2022 12 21.
Article in English | MEDLINE | ID: mdl-36453203

ABSTRACT

Aryl-urea substituted fatty acids are protonophores and mitochondrial uncouplers that utilise a urea-based synthetic anion transport moiety to carry out the protonophoric cycle. Herein we show that replacement of the urea group with carbamate, a functional group not previously reported to possess anion transport activity, produces analogues that retain the activity of their urea counterparts. Thus, the aryl-carbamate substituted fatty acids uncouple oxidative phosphorylation and inhibit ATP production by collapsing the mitochondrial proton gradient. Proton transport proceeds via self-assembly of the deprotonated aryl-carbamates into membrane permeable dimeric species, formed by intermolecular binding of the carboxylate group to the carbamate moiety. These results highlight the anion transport capacity of the carbamate functional group.


Subject(s)
Fatty Acids , Protons , Fatty Acids/metabolism , Carbamates/pharmacology , Carbamates/metabolism , Mitochondria/metabolism , Oxidative Phosphorylation
10.
J Neurochem ; 150(1): 88-106, 2019 07.
Article in English | MEDLINE | ID: mdl-30716176

ABSTRACT

Treatment with the dopamine (DA) precursor l-3,4-dihydroxyphenylalanine (l-DOPA) provides symptomatic relief arising from DA denervation in Parkinson's disease. Mounting evidence that DA autooxidation to neurotoxic quinones is involved in Parkinson's disease pathogenesis has raised concern about potentiation of oxidative stress by l-DOPA. The rate of DA quinone formation increases in the presence of excess redox-active iron (Fe), which is a pathological hallmark of Parkinson's disease. Conversely, l-DOPA has pH-dependent Fe-chelating properties, and may act to 'redox silence' Fe and partially allay DA autoxidation. We examined the effects of l-DOPA in three murine models of parkinsonian neurodegeneration: early-life Fe overexposure in wild-type mice, transgenic human (h)A53T mutant α-synuclein (α-syn) over-expression, and a combined 'multi-hit' model of Fe-overload in hA53T mice. We found that l-DOPA was neuroprotective and prevented age-related Fe accumulation in the substantia nigra pars compacta (SNc), similar to the mild-affinity Fe chelator clioquinol. Chronic l-DOPA treatment showed no evidence of increased oxidative stress in wild-type midbrain and normalized motor performance, when excess Fe was present. Similarly, l-DOPA also did not exacerbate protein oxidation levels in hA53T mice, with or without excess nigral Fe, and showed evidence of neuroprotection. The effects of l-DOPA in Fe-fed hA53T mice were somewhat muted, suggesting that Fe-chelation alone is insufficient to attenuate neuron loss in an animal model also recapitulating altered DA metabolism. In summary, we found no evidence in any of our model systems that l-DOPA treatment accentuated neurodegeneration, suggesting DA replacement therapy does not contribute to oxidative stress in the Parkinson's disease brain.


Subject(s)
Antiparkinson Agents/pharmacology , Brain/drug effects , Levodopa/pharmacology , Oxidative Stress/drug effects , Parkinson Disease/metabolism , Animals , Brain/pathology , Disease Models, Animal , Dopaminergic Neurons/drug effects , Dopaminergic Neurons/pathology , Humans , Iron/metabolism , Iron Overload , Mice , Mice, Transgenic , Nerve Degeneration/pathology , alpha-Synuclein
11.
FASEB J ; 31(12): 5246-5257, 2017 12.
Article in English | MEDLINE | ID: mdl-28798154

ABSTRACT

A saturated analog of the cytochrome P450-mediated ω-3-17,18-epoxide of ω-3-eicosapentaenoic acid (C20E) activated apoptosis in human triple-negative MDA-MB-231 breast cancer cells. This study evaluated the apoptotic mechanism of C20E. Increased cytosolic cytochrome c expression and altered expression of pro- and antiapoptotic B-cell lymphoma-2 proteins indicated activation of the mitochondrial pathway. Caspase-3 activation by C20E was prevented by pharmacological inhibition and silencing of the JNK and p38 MAP kinases (MAPK), upstream MAPK kinases MKK4 and MKK7, and the upstream MAPK kinase kinase apoptosis signal-regulating kinase 1 (ASK1). Silencing of the death receptor TNF receptor 1 (TNFR1), but not Fas, DR4, or DR5, and the adapters TRADD and TNF receptor-associated factor 2, but not Fas-associated death domain, prevented C20E-mediated apoptosis. B-cell lymphoma-2 homology 3-interacting domain death agonist (Bid) cleavage by JNK/p38 MAPK linked the extrinsic and mitochondrial pathways of apoptosis. In further studies, an antibody against the extracellular domain of TNFR1 prevented apoptosis by TNF-α but not C20E. These findings suggest that C20E acts intracellularly at TNFR1 to activate ASK1-MKK4/7-JNK/p38 MAPK signaling and to promote Bid-dependent mitochondrial disruption and apoptosis. In in vivo studies, tumors isolated from C20E-treated nu/nu mice carrying MDA-MB-231 xenografts showed increased TUNEL staining and decreased Ki67 staining, reflecting increased apoptosis and decreased proliferation, respectively. ω-3-Epoxy fatty acids like C20E could be incorporated into treatments for triple-negative breast cancers.-Dyari, H. R. E., Rawling, T., Chen, Y., Sudarmana, W., Bourget, K., Dwyer, J. M., Allison, S. E., Murray, M. A novel synthetic analogue of ω-3 17,18-epoxyeicosatetraenoic acid activates TNF receptor-1/ASK1/JNK signaling to promote apoptosis in human breast cancer cells.


Subject(s)
Arachidonic Acids/pharmacology , Arachidonic Acids/therapeutic use , Breast Neoplasms/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , MAP Kinase Kinase Kinase 5/metabolism , Receptors, Tumor Necrosis Factor/metabolism , Animals , Apoptosis/genetics , Apoptosis/physiology , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Caspase 3/metabolism , Cell Line, Tumor , Female , Humans , JNK Mitogen-Activated Protein Kinases/genetics , MAP Kinase Kinase Kinase 5/genetics , Mice , Mice, Inbred BALB C , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Receptors, Tumor Necrosis Factor/genetics , Receptors, Tumor Necrosis Factor, Type I/metabolism , TNF Receptor-Associated Death Domain Protein/metabolism , Tumor Necrosis Factor-alpha/metabolism , fas Receptor/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism
12.
Chem Res Toxicol ; 28(1): 92-102, 2015 Jan 20.
Article in English | MEDLINE | ID: mdl-25489883

ABSTRACT

The multikinase inhibitor sorafenib (SRF) is approved for the treatment of renal and hepatic carcinomas and is also undergoing evaluation in therapeutic combinations with other anticancer agents. SRF is generally well tolerated but produces severe toxicities in a significant proportion of patients by mechanisms that are largely unknown. It has been shown that cytochrome P450 (CYP) 3A4 has a major role in SRF biotransformation to the pharmacologically active N-oxide (SRF-Nox) and two other metabolites. In this study, we prepared the major metabolites of SRF and evaluated their further biotransformation by CYPs in relation to their capacity to produce cellular toxicity. CYP3A4 was also found to be the principal enzyme that mediated the secondary oxidation of SRF metabolites. However, the reduction of SRF-Nox to SRF was also found to be a significant reaction mediated by several CYPs, especially CYPs 2B6 and 1A1. In human liver-derived HepG2 cells, SRF effectively decreased ATP production to an extent greater than that of its metabolites. SRF also markedly altered the cell cycle distribution in HepG2 cells by decreasing the proportion in G0/G1 phase and increasing that in S and G2/M phases. In comparison, SRF metabolites minimally affected HepG2 cell cycle progression. These findings suggest that SRF, but not its metabolites, prevents cells from entering the cell cycle and also inhibits cycling cells from completing mitosis. Reduction of the major metabolite SRF-Nox back to SRF may mediate decreased cellular viability and contribute to adverse reactions in some individuals.


Subject(s)
Antineoplastic Agents/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Niacinamide/analogs & derivatives , Phenylurea Compounds/pharmacology , Protein Kinase Inhibitors/pharmacology , Biotransformation , Cell Cycle/drug effects , Cell Survival/drug effects , Cytochrome P-450 Enzyme Inhibitors/pharmacology , Hep G2 Cells , Humans , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Niacinamide/metabolism , Niacinamide/pharmacology , Phenylurea Compounds/metabolism , Sorafenib
13.
Drug Metab Dispos ; 42(11): 1851-7, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25165131

ABSTRACT

Solute carrier (SLC) transporters regulate the cellular influx and disposition of endogenous and xenobiotic compounds, including anticancer agents such as the multikinase inhibitors (MKIs). Recent evidence suggests that MKIs may also inhibit SLC-dependent transport of coadministered drugs, although present information on the relative susceptibilities of multiple SLC transporters is limited. This study evaluated 18 MKI drugs and metabolites as inhibitors of prototypic substrate uptake by 13 SLC transporters that were overexpressed in human embryonic kidney cells. Organic anion transporting polypeptides (OATPs) 1A2, 1B3, and 2B1, organic anion transporter 3 (OAT3), and organic cation transporter 1 (OCT1) were inhibited by most MKIs, whereas substrate uptake by OATP1B1, OAT1, 2, and 4, OCT2 and 3, and organic zwitterion/cation transporter 1 (OCTN1) was less susceptible to inhibition; OCTN2 was also inhibited by cediranib. In further studies, IC50 values were determined for the most effective MKIs, and erlotinib and cediranib were found to be potent competitive inhibitors of OATP2B1 (Ki = 41 nM) and OATP1A2 (Ki = 33 nM), respectively. From predictive approaches, several MKI-SLC interactions were found to be of potential in vivo significance.


Subject(s)
Carrier Proteins/physiology , Protein Kinase Inhibitors/pharmacology , Cells, Cultured , HEK293 Cells , Humans , Inhibitory Concentration 50
14.
Food Chem Toxicol ; 183: 114202, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38007213

ABSTRACT

Ionic liquids (ILs) are a class of low melting point salts with physicochemical properties that make them suitable for a range of industrial applications. Accumulating evidence suggests that certain ILs are cytotoxic and potential environmental pollutants, thus understanding the structural features that promote IL cytotoxicity is important. Amphiphilic ionic liquids (AmILs), a class of ILs with lipophilic N-alkyl chains, containing aromatic head groups are generally more cytotoxic than their aliphatic counterparts, however the impact of other head group properties are less clear. This study therefore sought to provide new structure activity relationship (SAR) insights regarding the role of the cationic head group on AmIL cytotoxicity. A series of AmILs bearing a range of structurally diverse aromatic cations varying in size, charge, and lipophilicity was synthesised and screened against human MDA-MB-231 breast cancer cells. It was found that larger and more lipophilic head groups increased cytotoxicity, although the magnitude of the changes were modest. The mitochondrial effects of representative ILs were assessed. The AmILs induced mitochondrial dysfunction in MDA-MB-231 cells at cytotoxic concentrations, suggesting that they target mitochondria. The new SAR information from this study may assist in the design of AmILs with controlled cytotoxicity.


Subject(s)
Ionic Liquids , Humans , Ionic Liquids/toxicity , Ionic Liquids/chemistry , Group Structure , Structure-Activity Relationship , Cations/chemistry
15.
Chem Biol Interact ; 396: 111042, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38735455

ABSTRACT

Ionic liquids (ILs) are a class of low melting point salts with physicochemical properties suitable for a range of industrial applications such as chemical processing and battery design. Major challenges to the wide-scale adoption of ILs in industry include their eco- and cytotoxic effects, however, this opens up the possibility of the use of ILs use as novel anticancer agents. Understanding the structural features that promote IL cytotoxicity is therefore important. Key structural features that can impact IL cytotoxicity include size and lipophilicity of the cationic head group. In this study, the cytotoxic effects of acridinium-based ILs containing relatively large tri- and tetracyclic cations were evaluated. It was found that 9-phenylacridinium-based ILs are potent cytotoxic agents that reduce the viability of human MDA-MB-231 breast cancer cells with IC50 concentrations in the nanomolar range. In mechanistic studies, it was found that unlike the pyridinium-based analogue, [C16Py][I], acridinium-based ILs did not inhibit oxidative phosphorylation or induce reactive oxygen species formation, and may instead target other mitochondrial processes or components such as mitochondrial DNA.


Subject(s)
Acridines , Ionic Liquids , Reactive Oxygen Species , Humans , Ionic Liquids/chemistry , Ionic Liquids/pharmacology , Acridines/chemistry , Acridines/pharmacology , Structure-Activity Relationship , Cell Line, Tumor , Reactive Oxygen Species/metabolism , Cell Survival/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Oxidative Phosphorylation/drug effects
16.
ChemMedChem ; : e202400281, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38945837

ABSTRACT

The cancer cell mitochondrion could be a promising target for the development of new anticancer agents. 16-([3-chloro-5-(trifluoromethyl)-phenyl]carbamoylamino)hexadecanoic acid (2) is a novel aryl-urea fatty acid that targets the mitochondrion in MDA-MB-231 breast cancer cells and activates cell death. In the present study, the relationships between alkyl chain length in 2 analogues, mitochondrial disruption and cell killing were evaluated. The chain-contracted C13-analogue 7 c optimally disrupted the mitochondrial membrane potential (IC50 4.8±0.8 µM). In addition, annexin V-FITC/7-AAD assays demonstrated that 7 c was the most effective cell killing analogue and C11 BODIPY (581/591) assays demonstrated that 7 c was also most effective in generating reactive oxygen species in MDA-MB-231 cells. Together, carbon chain length is a key factor that determines the capacity of 2 analogues to disrupt the mitochondrial membrane, induce the production of reactive oxygen species and kill breast cancer cells. As an aryl-urea with enhanced activity and improved drug-like properties, 7 c may be a suitable lead molecule for entry into a program of development of these molecules as anticancer agents.

17.
Front Mol Neurosci ; 17: 1392715, 2024.
Article in English | MEDLINE | ID: mdl-38979476

ABSTRACT

Zinc is a ubiquitous contaminant in many buffers, purified products and common labware that has previously been suggested to impact on the results of functional GlyR studies and may inadvertently cause the effectiveness of some GlyR modulators to be over-estimated. This could greatly impact the assessment of potential drug-candidates and contribute to the reduced effectiveness of compounds that reach clinical stages. This is especially true for GlyR modulators being developed for pain therapeutics due to the changes in spinal zinc concentrations that have been observed during chronic pain conditions. In this study we use two-electrode voltage clamp electrophysiology to evaluate the metal chelators tricine and Ca-EDTA, and show that tricine produces inhibitory effects at GlyRα1 that are not mediated by zinc. We also utilized the zinc insensitive W170S mutation as a tool to validate metal chelators and confirm that zinc contamination has not impacted the examination of lipid modulators previously developed by our lab. This study helps to further develop methods to negate the impact of contaminating zinc in functional studies of GlyRs which should be incorporated into future studies that seek to characterize the activity of novel modulators at GlyRs.

18.
Int J Biochem Cell Biol ; 171: 106571, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38608921

ABSTRACT

Current treatment options for triple-negative breast cancer (TNBC) are limited to toxic drug combinations of low efficacy. We recently identified an aryl-substituted fatty acid analogue, termed CTU, that effectively killed TNBC cells in vitro and in mouse xenograft models in vivo without producing toxicity. However, there was a residual cell population that survived treatment. The present study evaluated the mechanisms that underlie survival and renewal in CTU-treated MDA-MB-231 TNBC cells. RNA-seq profiling identified several pro-inflammatory signaling pathways that were activated in treated cells. Increased expression of cyclooxygenase-2 and the cytokines IL-6, IL-8 and GM-CSF was confirmed by real-time RT-PCR, ELISA and Western blot analysis. Increased self-renewal was confirmed using the non-adherent, in vitro colony-forming mammosphere assay. Neutralizing antibodies to IL-6, IL-8 and GM-CSF, as well as cyclooxygenase-2 inhibition suppressed the self-renewal of MDA-MB-231 cells post-CTU treatment. IPA network analysis identified major NF-κB and XBP1 gene networks that were activated by CTU; chemical inhibitors of these pathways and esiRNA knock-down decreased the production of pro-inflammatory mediators. NF-κB and XBP1 signaling was in turn activated by the endoplasmic reticulum (ER)-stress sensor inositol-requiring enzyme 1 (IRE1), which mediates the unfolded protein response. Co-treatment with an inhibitor of IRE1 kinase and RNase activities, decreased phospho-NF-κB and XBP1s expression and the production of pro-inflammatory mediators. Further, IRE1 inhibition also enhanced apoptotic cell death and prevented the activation of self-renewal by CTU. Taken together, the present findings indicate that the IRE1 ER-stress pathway is activated by the anti-cancer lipid analogue CTU, which then activates secondary self-renewal in TNBC cells.


Subject(s)
Cell Survival , Endoplasmic Reticulum Stress , Endoribonucleases , Protein Serine-Threonine Kinases , Female , Humans , Cell Line, Tumor , Cell Survival/drug effects , Endoplasmic Reticulum Stress/drug effects , Endoribonucleases/metabolism , Endoribonucleases/genetics , Fatty Acids/metabolism , MDA-MB-231 Cells , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Signal Transduction/drug effects , Triple Negative Breast Neoplasms/pathology , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/drug therapy
19.
Biomedicines ; 12(2)2024 Feb 19.
Article in English | MEDLINE | ID: mdl-38398064

ABSTRACT

Autophagy is a form of programmed cell degradation that enables the maintenance of homeostasis in response to extracellular stress stimuli. Autophagy is primarily activated by starvation and mediates the degradation, removal, or recycling of cell cytoplasm, organelles, and intracellular components in eukaryotic cells. Autophagy is also involved in the pathogenesis of human diseases, including several cancers. Human uveal melanoma (UM) is the primary intraocular malignancy in adults and has an extremely poor prognosis; at present there are no effective therapies. Several studies have suggested that autophagy is important in UM. By understanding the mechanisms of activation of autophagy in UM it may be possible to develop biomarkers to provide more definitive disease prognoses and to identify potential drug targets for the development of new therapeutic strategies. This article reviews the current information regarding autophagy in UM that could facilitate biomarker and drug development.

20.
J Pharm Pharm Sci ; 16(2): 238-53, 2013.
Article in English | MEDLINE | ID: mdl-23958193

ABSTRACT

Intercellular communication is essential to maintain vital physiological activities and to regulate the organism's phenotype. There are a number of ways in which cells communicate with one another. This can occur via autocrine signaling, endocrine signaling or by the transfer of molecular mediators across gap junctions. More recently communication via microvesicular shedding has gained important recognition as a significant pathway by which cells can coordinate the spread and dominance of selective traits within a population. Through this communication apparatus, cells can now acquire and secure a survival advantage, particularly in the context of malignant disease. This review aims to highlight some of the functions and implications of microparticles in physiology of various disease states, and present a novel therapeutic strategy through the regulation of microparticle production.


Subject(s)
Cell-Derived Microparticles/metabolism , Animals , Blood Coagulation Disorders/metabolism , Diabetes Mellitus/metabolism , Drug Resistance, Neoplasm , HIV Infections/metabolism , Humans , Malaria, Cerebral/metabolism , Neoplasms/metabolism
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