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1.
J Inorg Biochem ; 259: 112632, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38950482

RESUMO

Aminophenol dioxygenases (APDO) are mononuclear nonheme iron enzymes that utilize dioxygen (O2) to catalyze the conversion of o-aminophenols to 2-picolinic acid derivatives in metabolic pathways. This study describes the synthesis and O2 reactivity of two synthetic models of substrate-bound APDO: [FeII(TpMe2)(tBu2APH)] (1) and [FeII(TpMe2)(tBuAPH)] (2), where TpMe2 = hydrotris(3,5-dimethylpyrazole-1-yl)borate, tBu2APH = 4,6-di-tert-butyl-2-aminophenolate, and tBuAPH2 = 4-tert-butyl-2-aminophenolate. Both Fe(II) complexes behave as functional APDO mimics, as exposure to O2 results in oxidative CC bond cleavage of the o-aminophenolate ligand. The ring-cleaved products undergo spontaneous cyclization to give substituted 2-picolinic acids, as verified by 1H NMR spectroscopy, mass spectrometry, and X-ray crystallography. Reaction of the APDO models with O2 at low temperature reveals multiple intermediates, which were probed with UV-vis absorption, electron paramagnetic resonance (EPR), Mössbauer (MB), and resonance Raman (rRaman) spectroscopies. The most stable intermediate at -70 °C in THF exhibits multiple isotopically-sensitive features in rRaman samples prepared with 16O2 and 18O2, confirming incorporation of O2-derived atom(s) into its molecular structure. Insights into the geometric structures, electronic properties, and spectroscopic features of the observed intermediates were obtained from density functional theory (DFT) calculations. Although functional APDO models have been previously reported, this is the first time that an oxygenated ligand-based radical has been detected and spectroscopically characterized in the ring-cleaving mechanism of a relevant synthetic system.


Assuntos
Aminofenóis , Dioxigenases , Oxigênio , Oxigênio/química , Oxigênio/metabolismo , Dioxigenases/metabolismo , Dioxigenases/química , Aminofenóis/química , Oxirredução , Complexos de Coordenação/química , Ácidos Picolínicos/química , Teoria da Densidade Funcional , Cristalografia por Raios X
2.
Toxicon ; 247: 107836, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-38945217

RESUMO

The venoms of Australasian elapid snakes are known to possess coagulant activity, including some with strong procoagulant activity and others with anticoagulant activity, although the latter are less well known. This study investigates the anticoagulant activity of Australasian elapid snake venoms, and whether this activity is neutralised by commercial snake antivenom and varespladib (PLA2 inhibiting agent). Clotting assays were completed for 34 species of Australasian elapids. Antivenom neutralisation assays with tiger snake antivenom (TSAV) were performed on five species to determine if there was cross-neutralisation. Varespladib neutralisation assays were also completed for the same five species. All Pseudechis species venoms had anticoagulant activity, except P. porphyriacus, which was procoagulant. Pseudechis species venoms had similar anticoagulant potency ranging from the most potent P. colletti venom to the least potent P. butleri venom. The three Austrelaps (copperhead) species venoms were the next most potent anticoagulants. Six further snakes, Elapognathus coronatus, Acanthophis pyrrhus, A. antarcticus, Suta suta, Denisonia devisi and D. maculata, had weaker anticoagulant activity, except for D. maculata which had similar anticoagulant activity to Pseudechis species. Tiger Snake Antivenom (1200mU/mL) neutralised the anticoagulant effect of P. australis for concentrations up to 1 mg/mL. TSAV (1200mU/mL) also neutralised P. colletti, D. maculata, A. superbus and A. pyrrhus venoms at their EC50, demonstrating cross neutralisation. Varespladib neutralised the anticoagulant effect of P. australis venom at 5 µM and for venoms of P. colletti, D. maculata, A. superbus and A. pyrrhus. We found anticoagulant activity to be present in six genera of Australasian snakes at low concentrations, which can be completely neutralised by both antivenom and varespladib. Anticoagulant activity in Australian elapid venoms was associated with species possessing high PLA2 activity without procoagulant snake venom serine proteases.


Assuntos
Anticoagulantes , Antivenenos , Venenos Elapídicos , Antivenenos/farmacologia , Animais , Anticoagulantes/farmacologia , Elapidae , Cetoácidos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Austrália , Humanos , Acetatos , Indóis
3.
Dis Esophagus ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769843

RESUMO

Neoadjuvant cancer treatment (NCT) reduces both physical fitness and physical activity (PA) levels, which can increase the risk of adverse outcomes in cancer patients. This study aims to determine the effect of exercise prehabilitation on PA and sedentary behavior (SB) in patients undergoing NCT and surgery for esophagogastric malignancies. This study is a randomized pragmatic controlled multi-center trial conducted across three Irish hospitals. Participants were aged ≥18 years scheduled for esophagectomy or gastrectomy and were planned for NCT and surgery. Participants were randomized to an exercise prehabilitation group (EX) that commenced following cancer diagnosis, continued to the point of surgery, and resumed following recovery from surgery for 6 weeks or to usual care (UC) who received routine treatment. The primary outcome measures were PA and SB. Between March 2019 and December 2020, 71 participants were recruited: EX (n = 36) or UC (n = 35). No significant differences were found between the EX group and UC group on levels of PA or SBs across all measured timepoints. Significant decreases in moderate-vigorous physical activity levels (MVPAs) were found between baseline and post-surgery (P = 0.028), pre-surgery and post-surgery (P = 0.001) and pre-surgery and 6-week follow-up (P = 0.022) for all participants. Step count also significantly decreased between pre-surgery and post-surgery (P < 0.001). Baseline aerobic fitness was positively associated to PA levels and negatively associated with SB. Esophagogastric cancer patients have lower than recommended levels of PA at the time of diagnosis and this decreased further following completion of NCT. An optional home- or group-based exercise intervention was not effective in improving PA levels or behaviors across the cancer treatment journey.

4.
Circ Res ; 134(10): 1259-1275, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38597112

RESUMO

BACKGROUND: GPCRs (G-protein-coupled receptors) play a central role in the regulation of smooth muscle cell (SMC) contractility, but the function of SMC-expressed orphan GPCR class C group 5 member C (GPRC5C) is unclear. The aim of this project is to define the role of GPRC5C in SMC in vitro and in vivo. METHODS: We studied the role of GPRC5C in the regulation of SMC contractility and differentiation in human and murine SMC in vitro, as well as in tamoxifen-inducible, SMC-specific GPRC5C knockout mice under basal conditions and in vascular disease in vivo. RESULTS: Mesenteric arteries from tamoxifen-inducible, SMC-specific GPRC5C knockout mice showed ex vivo significantly reduced angiotensin II (Ang II)-dependent calcium mobilization and contraction, whereas responses to other relaxant or contractile factors were normal. In vitro, the knockdown of GPRC5C in human aortic SMC resulted in diminished Ang II-dependent inositol phosphate production and lower myosin light chain phosphorylation. In line with this, tamoxifen-inducible, SMC-specific GPRC5C knockout mice showed reduced Ang II-induced arterial hypertension, and acute inactivation of GPRC5C was able to ameliorate established arterial hypertension. Mechanistically, we show that GPRC5C and the Ang II receptor AT1 dimerize, and knockdown of GPRC5C resulted in reduced binding of Ang II to AT1 receptors in HEK293 cells, human and murine SMC, and arteries from tamoxifen-inducible, SMC-specific GPRC5C knockout mice. CONCLUSIONS: Our data show that GPRC5C regulates Ang II-dependent vascular contraction by facilitating AT1 receptor-ligand binding and signaling.


Assuntos
Angiotensina II , Músculo Liso Vascular , Receptores Acoplados a Proteínas G , Animais , Humanos , Masculino , Camundongos , Angiotensina II/farmacologia , Células Cultivadas , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertensão/induzido quimicamente , Hipertensão/genética , Artérias Mesentéricas/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Muscular , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Vasoconstrição
5.
EMBO Rep ; 25(4): 1835-1858, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38429578

RESUMO

Cancer cachexia is a tumour-induced wasting syndrome, characterised by extreme loss of skeletal muscle. Defective mitochondria can contribute to muscle wasting; however, the underlying mechanisms remain unclear. Using a Drosophila larval model of cancer cachexia, we observed enlarged and dysfunctional muscle mitochondria. Morphological changes were accompanied by upregulation of beta-oxidation proteins and depletion of muscle glycogen and lipid stores. Muscle lipid stores were also decreased in Colon-26 adenocarcinoma mouse muscle samples, and expression of the beta-oxidation gene CPT1A was negatively associated with muscle quality in cachectic patients. Mechanistically, mitochondrial defects result from reduced muscle insulin signalling, downstream of tumour-secreted insulin growth factor binding protein (IGFBP) homologue ImpL2. Strikingly, muscle-specific inhibition of Forkhead box O (FOXO), mitochondrial fusion, or beta-oxidation in tumour-bearing animals preserved muscle integrity. Finally, dietary supplementation with nicotinamide or lipids, improved muscle health in tumour-bearing animals. Overall, our work demonstrates that muscle FOXO, mitochondria dynamics/beta-oxidation and lipid utilisation are key regulators of muscle wasting in cancer cachexia.


Assuntos
Neoplasias do Colo , Proteínas de Drosophila , Insulinas , Camundongos , Animais , Humanos , Caquexia/etiologia , Caquexia/metabolismo , Drosophila/metabolismo , Dinâmica Mitocondrial , Atrofia Muscular/patologia , Músculo Esquelético/metabolismo , Neoplasias do Colo/metabolismo , Insulinas/metabolismo , Lipídeos , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
6.
J Cachexia Sarcopenia Muscle ; 14(5): 1987-2002, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37574254

RESUMO

There is increasing evidence that neurodegenerative disorders including the Parkinsonian syndromes are associated with impaired skeletal muscle health, manifesting as wasting and weakness. Many of the movement problems, lack of muscle strength and reduction in quality of life that are characteristic of these syndromes can be attributed to impairments in skeletal muscle health, but this concept has been grossly understudied and represents an important area of unmet clinical need. This review describes the changes in skeletal muscle health in idiopathic Parkinson's disease and in two atypical Parkinsonian syndromes, the most aggressive synucleinopathy multiple system atrophy, and the tauopathy progressive supranuclear palsy. The pathogenesis of the skeletal muscle changes is described, including the contribution of impairments to the central and peripheral nervous system and intrinsic alterations. Pharmacological interventions targeting the underlying molecular mechanisms with therapeutic potential to improve skeletal muscle health in affected patients are also discussed. Although little is known about the mechanisms underlying these conditions, current evidence implicates multiple pathways and processes, highlighting the likely need for combination therapies to protect muscle health and emphasizing the merit of personalized interventions for patients with different physical capacities at different stages of their disease. As muscle fatigue is often experienced by patients prior to diagnosis, the identification and measurement of this symptom and related biomarkers to identify early signs of disease require careful interrogation, especially for multiple system atrophy and progressive supranuclear palsy where diagnosis is often made several years after onset of symptoms and only confirmed post-mortem. We propose a multidisciplinary approach for early diagnosis and implementation of personalized interventions to preserve muscle health and improve quality of life for patients with typical and atypical Parkinsonian syndromes.

7.
Am J Physiol Cell Physiol ; 324(2): C205-C221, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36534500

RESUMO

Cancer cachexia is common in many cancers and the loss of skeletal muscle mass compromises the response to therapies and quality of life. A contributing mechanism is oxidative stress and compounds able to attenuate it may be protective. Sulforaphane (SFN), a natural antioxidant in cruciferous vegetables, activates nuclear factor erythroid 2-related factor 2 (Nrf2) signaling to decrease oxidative stress. Although SFN has potential as a cancer therapeutic, whether it can attenuate muscle wasting in the absence or presence of chemotherapy is unknown. In healthy C2C12 myotubes, SFN administration for 48 h induced hypertrophy through increased myoblast fusion via Nrf2 and ERK signaling. To determine whether SFN could attenuate wasting induced by cancer cells, myotubes were cocultured with or without Colon-26 (C-26) cancer cells for 48 h and treated with 5-fluorouracil (5-FU, 5 µM) or vehicle (DMSO). SFN (10 µM) or DMSO was added for the final 24 h. Coculture with cancer cells in the absence and presence of 5-FU reduced myotube width by ∼30% (P < 0.001) and ∼20% (P < 0.01), respectively, which was attenuated by SFN (P < 0.05). Exposure to C-26 conditioned media reduced myotube width by 15% (P < 0.001), which was attenuated by SFN. Western immunoblotting and qRT-PCR confirmed activation of Nrf2 signaling and antioxidant genes. Coadministration of Nrf2 inhibitors (ML-385) or MEK inhibitors (PD184352) revealed that SFN's attenuation of atrophy was blocked by ERK inhibition. These data support the chemoprotective and antioxidative function of SFN in myotubes, highlighting its therapeutic potential for cancer-related muscle wasting.


Assuntos
Antioxidantes , Neoplasias , Humanos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Dimetil Sulfóxido/metabolismo , Qualidade de Vida , Fibras Musculares Esqueléticas/metabolismo , Estresse Oxidativo , Atrofia Muscular/patologia , Neoplasias/metabolismo , Fluoruracila/farmacologia
8.
Ir J Med Sci ; 192(2): 527-531, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35415773

RESUMO

BACKGROUND: Ireland has a mixed model of healthcare delivery with a public healthcare system funded by general taxation and a large private healthcare insurance system, covering 43% of the population in 2012 and 2016. We set out to examine disparities in outcomes among patients with breast cancer treated in a private hospital compared to national outcomes over a comparable period. METHODS: Medical records of patients diagnosed with early (Stage 1-3 as per AJCC version 5) breast cancer between 2010 and 2015 at Bon Secours Hospital, Cork, Ireland were reviewed. Staging was confirmed and 5-year disease specific survival (DSS) and overall survival (OS) were calculated. DSS was compared to 5-year net survival (NS) figures from the National Cancer Registry of Ireland (NCRI) for a comparable period (2010-2014). RESULTS: DSS (Bon Secours) and NS (NCRI) are summarized in Table 5 and Fig. 2. 5-year survival figures are numerically higher in the private hospital compared with national data for individual stage. Taking stages 1 to 3 combined, the 95% confidence intervals do not cross, indicating statistical significance. CONCLUSIONS: We found evidence of superior outcomes in patients with early breast cancer treated at a private hospital compared with national outcome figures. This was demonstrated in 'all comers' (stages 1-3 combined), and particularly in patients with stage 3 breast cancer. Potential reasons for this disparity include differences in socioeconomic status, health-seeking behaviours and/or underlying health status between the two populations included. Differences in extent or timeliness of access to therapies may also contribute.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Hospitais Privados , Atenção à Saúde , Irlanda/epidemiologia , Disparidades em Assistência à Saúde
9.
J Clin Pathol ; 76(9): 612-617, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35428674

RESUMO

AIMS: The aim of this quality improvement project was to improve the turnaround time of B-raf proto-oncogene (BRAF) mutation testing in patients with malignant melanoma to support oncologists in making timely treatment decisions. METHODS: This is a prospective in-house verification of the Idylla BRAF test as compared with DNA panel next-generation sequencing (NGS) performed at an external laboratory. RESULTS: The Idylla BRAF test had an overall concordance of 95% compared with NGS. This was considered sufficiently good for use in patients with a poor performance status who were at risk of rapid clinical deterioration. Reliable results can be generated using the Idylla BRAF test in tissue sections with tumour neoplastic cell content below 50%. We present a multidisciplinary clinical care algorithm to support dual testing. CONCLUSIONS: The Idylla BRAF test has the potential to make a significant positive impact on progression-free survival of malignant melanoma patients due to its rapid turnaround time. The Idylla BRAF test can be used as an adjunct to NGS for timely management of patients, particularly those with a poor performance status at presentation.


Assuntos
Melanoma , Proteínas Proto-Oncogênicas B-raf , Humanos , Proteínas Proto-Oncogênicas B-raf/genética , Patologia Molecular , Fluxo de Trabalho , Estudos Prospectivos , Melhoria de Qualidade , Análise Mutacional de DNA/métodos , Melanoma/genética , Melanoma/terapia , Melanoma/patologia , Mutação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Melanoma Maligno Cutâneo
10.
J Physiol ; 600(16): 3749-3774, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35837833

RESUMO

We investigated whether digoxin lowered muscle Na+ ,K+ -ATPase (NKA), impaired muscle performance and exacerbated exercise K+ disturbances. Ten healthy adults ingested digoxin (0.25 mg; DIG) or placebo (CON) for 14 days and performed quadriceps strength and fatiguability, finger flexion (FF, 105%peak-workrate , 3 × 1 min, fourth bout to fatigue) and leg cycling (LC, 10 min at 33% V O 2 peak ${\rm{V}}_{{{\rm{O}}}_{\rm{2}}{\rm{peak}}}$ and 67% V O 2 peak ${\rm{V}}_{{{\rm{O}}}_{\rm{2}}{\rm{peak}}}$ , 90% V O 2 peak ${\rm{V}}_{{{\rm{O}}}_{\rm{2}}{\rm{peak}}}$ to fatigue) trials using a double-blind, crossover, randomised, counter-balanced design. Arterial (a) and antecubital venous (v) blood was sampled (FF, LC) and muscle biopsied (LC, rest, 67% V O 2 peak ${\rm{V}}_{{{\rm{O}}}_{\rm{2}}{\rm{peak}}}$ , fatigue, 3 h after exercise). In DIG, in resting muscle, [3 H]-ouabain binding site content (OB-Fab ) was unchanged; however, bound-digoxin removal with Digibind revealed total ouabain binding (OB+Fab ) increased (8.2%, P = 0.047), indicating 7.6% NKA-digoxin occupancy. Quadriceps muscle strength declined in DIG (-4.3%, P = 0.010) but fatiguability was unchanged. During LC, in DIG (main effects), time to fatigue and [K+ ]a were unchanged, whilst [K+ ]v was lower (P = 0.042) and [K+ ]a-v greater (P = 0.004) than in CON; with exercise (main effects), muscle OB-Fab was increased at 67% V O 2 peak ${\rm{V}}_{{{\rm{O}}}_{\rm{2}}{\rm{peak}}}$ (per wet-weight, P = 0.005; per protein P = 0.001) and at fatigue (per protein, P = 0.003), whilst [K+ ]a , [K+ ]v and [K+ ]a-v were each increased at fatigue (P = 0.001). During FF, in DIG (main effects), time to fatigue, [K+ ]a , [K+ ]v and [K+ ]a-v were unchanged; with exercise (main effects), plasma [K+ ]a , [K+ ]v , [K+ ]a-v and muscle K+ efflux were all increased at fatigue (P = 0.001). Thus, muscle strength declined, but functional muscle NKA content was preserved during DIG, despite elevated plasma digoxin and muscle NKA-digoxin occupancy, with K+ disturbances and fatiguability unchanged. KEY POINTS: The Na+ ,K+ -ATPase (NKA) is vital in regulating skeletal muscle extracellular potassium concentration ([K+ ]), excitability and plasma [K+ ] and thereby also in modulating fatigue during intense contractions. NKA is inhibited by digoxin, which in cardiac patients lowers muscle functional NKA content ([3 H]-ouabain binding) and exacerbates K+ disturbances during exercise. In healthy adults, we found that digoxin at clinical levels surprisingly did not reduce functional muscle NKA content, whilst digoxin removal by Digibind antibody revealed an ∼8% increased muscle total NKA content. Accordingly, digoxin did not exacerbate arterial plasma [K+ ] disturbances or worsen fatigue during intense exercise, although quadriceps muscle strength was reduced. Thus, digoxin treatment in healthy participants elevated serum digoxin, but muscle functional NKA content was preserved, whilst K+ disturbances and fatigue with intense exercise were unchanged. This resilience to digoxin NKA inhibition is consistent with the importance of NKA in preserving K+ regulation and muscle function.


Assuntos
Digoxina , Ouabaína , Adulto , Digoxina/metabolismo , Fadiga , Humanos , Músculo Esquelético/fisiologia , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo
11.
Cells ; 11(5)2022 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-35269446

RESUMO

The mechanical homeostasis of tissues can be altered in response to trauma or disease, such as cancer, resulting in altered mechanotransduction pathways that have been shown to impact tumor development, progression, and the efficacy of therapeutic approaches. Specifically, ovarian cancer progression is parallel to an increase in tissue stiffness and fibrosis. With in vivo models proving difficult to study, tying tissue mechanics to altered cellular and molecular properties necessitate advanced, tunable, in vitro 3D models able to mimic normal and tumor mechanic features. First, we characterized normal human ovary and high-grade serous (HGSC) ovarian cancer tissue stiffness to precisely mimic their mechanical features on collagen I-based sponge scaffolds, soft (NS) and stiff (MS), respectively. We utilized three ovarian cancer cell lines (OVCAR-3, Caov-3, and SKOV3) to evaluate changes in viability, morphology, proliferation, and sensitivity to doxorubicin and liposomal doxorubicin treatment in response to a mechanically different microenvironment. High substrate stiffness promoted the proliferation of Caov-3 and SKOV3 cells without changing their morphology, and upregulated mechanosensors YAP/TAZ only in SKOV3 cells. After 7 days in culture, both OVCAR3 and SKOV3 decreased the MS scaffold storage modulus (stiffness), suggesting a link between cell proliferation and the softening of the matrix. Finally, high matrix stiffness resulted in higher OVCAR-3 and SKOV3 cell cytotoxicity in response to doxorubicin. This study demonstrates the promise of biomimetic porous scaffolds for effective inclusion of mechanical parameters in 3D cancer modeling. Furthermore, this work establishes the use of porous scaffolds for studying ovarian cancer cells response to mechanical changes in the microenvironment and as a meaningful platform from which to investigate chemoresistance and drug response.


Assuntos
Apoptose , Neoplasias Ovarianas , Linhagem Celular Tumoral , Doxorrubicina , Matriz Extracelular/metabolismo , Feminino , Humanos , Mecanotransdução Celular , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Microambiente Tumoral
12.
Antioxidants (Basel) ; 11(2)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35204066

RESUMO

Cancer cachexia is the progressive muscle wasting and weakness experienced by many cancer patients. It can compromise the response to gold standard cancer therapies, impair functional capacity and reduce overall quality of life. Cancer cachexia accounts for nearly one-third of all cancer-related deaths and has no effective treatment. The pathogenesis of cancer cachexia and its progression is multifactorial and includes increased oxidative stress derived from both the tumor and the host immune response. Antioxidants have therapeutic potential to attenuate cancer-related muscle loss, with polyphenols, a group of plant-derived antioxidants, being the most widely investigated. This review describes the potential of these plant-derived antioxidants for treating cancer cachexia.

13.
PLoS One ; 17(2): e0263845, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35143561

RESUMO

ADP-ribosylation factor 6 small GTPase plays an important role in cell migration, invasion and angiogenesis, which are the hallmarks of cancer. Although alterations in ARF6 expression and activity have been linked to metastatic cancer in one or two tissues, the expression of ARF6 in cancers over a wide range of tissues has not been studied so far. In this report, we analysed the expression of ARF6 mRNA in cancers and corresponding healthy controls from 17 different tissues by real-time qualitative polymerase chain reaction (RT-qPCR). We further evaluated ARF6 protein expression in oesophageal adenocarcinoma (EAC) tissue microarray cores by immunohistochemistry. The ARF6 gene expression levels are highly variable between healthy and cancer tissues. Our findings suggest that the ARF6 gene expression is up-regulated highest in oesophageal cancer. In EAC TMAs, ARF6 protein expression increase correlated with EAC progression. This is the first study to investigate ARF6 gene expression in a wide array of cancer tissues and demonstrate that ARF6 expression, at both mRNA and protein levels, is significantly upregulated in higher grades of EAC, which may be useful in targeting ARF6 for cancer diagnostic and therapeutic purposes.


Assuntos
Fator 6 de Ribosilação do ADP/genética , Fator 6 de Ribosilação do ADP/metabolismo , Adenocarcinoma/patologia , Neoplasias Esofágicas/patologia , Regulação para Cima , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Estudos de Casos e Controles , Progressão da Doença , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Gradação de Tumores , Análise Serial de Tecidos
14.
Cancers (Basel) ; 13(5)2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33800911

RESUMO

Endometrial cancer (EC) is the sixth most prevalent female cancer globally and although high rates of success are achieved when diagnosed at an early stage, the 5-year survival rate for cancers diagnosed at Stages II-IV is below 50%. Improving patient outcomes will necessitate the introduction of novel therapies to the clinic. Pan-cyclin-dependent kinase inhibitors (CDKis) have been explored as therapies for a range of cancers due to their ability to simultaneously target multiple key cellular processes, such as cell cycle progression, transcription, and DNA repair. Few studies, however, have reported on their potential for the treatment of EC. Herein, we examined the effects of the pan-CDKi dinaciclib in primary cells isolated directly from tumors and EC cell lines. Dinaciclib was shown to elicit a bimodal action in EC cell lines, disrupting both cell cycle progression and phosphorylation of the RNA polymerase carboxy terminal domain, with a concomitant reduction in Bcl-2 expression. Furthermore, the therapeutic potential of combining dinaciclib and cisplatin was explored, with the drugs demonstrating synergy at specific doses in Type I and Type II EC cell lines. Together, these results highlight the potential of dinaciclib for use as an effective EC therapy.

15.
Am J Physiol Cell Physiol ; 320(6): C956-C965, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33729835

RESUMO

The dystrophin-glycoprotein complex (DGC) is a multiprotein structure required to maintain muscle fiber membrane integrity, transmit force by linking the actin cytoskeleton with the extracellular matrix, and maintain muscle homeostasis. Membrane localization of dystrophin is perturbed in muscles wasting as a consequence of cancer cachexia, tenotomy, and advanced aging, which are all associated with low level, chronic inflammation. Strategies to preserve dystrophin expression at the sarcolemma might therefore combat muscle wasting. Phosphorylation of dystrophin serine 3059 (S3059) enhances the interaction between dystrophin and ß-dystroglycan. To test the contribution of amino acid phosphorylation to muscle fiber size changes, dystrophin constructs with phospho-null and phosphomimetic mutations were transfected into C2C12 muscle cells or AAV-293 cells in the presence or absence of kinase inhibitors/activators to assess effects on myotube diameter and protein function. Overexpression of a dystrophin construct with a phospho-null mutation at S3059 in vitro reduced myotube size in healthy C2C12 cells. Conversely overexpression of a phosphomimetic mutation at S3059 attenuated inflammation-induced myotube atrophy. Increased ERK activation by addition of phorbol myristate acetate (PMA) also reduced inflammation-associated myotube atrophy and increased the interaction between dystrophin and ß-dystroglycan. These findings demonstrate a link between increased ERK activation, dystrophin S3059 phosphorylation, stabilization of the DGC, and the regulation of muscle fiber size. Interventions that increase dystrophin S3059 phosphorylation to promote stronger binding of dystrophin to ß-dystroglycan may have therapeutic potential for attenuation of inflammation-associated muscle wasting.


Assuntos
Distrofina/metabolismo , Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Fibras Musculares Esqueléticas/metabolismo , Fosforilação/fisiologia , Animais , Caquexia/metabolismo , Membrana Celular/metabolismo , Distroglicanas/metabolismo , Matriz Extracelular/metabolismo , Humanos , Glicoproteínas de Membrana/metabolismo , Camundongos , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Sarcolema/metabolismo
17.
Twin Res Hum Genet ; 22(6): 438-445, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31767048

RESUMO

Twins Research Australia (TRA) is a community of twins and researchers working on health research to benefit everyone, including twins. TRA leads multidisciplinary research through the application of twin and family study designs, with the aim of sustaining long-term twin research that, both now and in the future, gives back to the community. This article summarizes TRA's recent achievements and future directions, including new methodologies addressing causation, linkage to health, economic and educational administrative datasets and to geospatial data to provide insight into health and disease. We also explain how TRA's knowledge translation and exchange activities are key to communicating the impact of twin studies to twins and the wider community. Building researcher capability, providing registry resources and partnering with all key stakeholders, particularly the participants, are important for how TRA is advancing twin research to improve health outcomes for society. TRA provides researchers with open access to its vibrant volunteer membership of twins, higher order multiples (multiples) and families who are willing to consider participation in research. Established four decades ago, this resource facilitates and supports research across multiple stages and a breadth of health domains.


Assuntos
Pesquisa Biomédica , Doenças em Gêmeos/epidemiologia , Sistema de Registros/estatística & dados numéricos , Projetos de Pesquisa/normas , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Austrália/epidemiologia , Doenças em Gêmeos/genética , Doenças em Gêmeos/patologia , Humanos , Incidência , Inquéritos e Questionários
18.
Cancer Res ; 79(4): 706-719, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30420474

RESUMO

Cancer cachexia is a multifactorial syndrome characterized by a progressive loss of skeletal muscle mass associated with significant functional impairment. Cachexia robs patients of their strength and capacity to perform daily tasks and live independently. Effective treatments are needed urgently. Here, we investigated the therapeutic potential of activating the "alternative" axis of the renin-angiotensin system, involving ACE2, angiotensin-(1-7), and the mitochondrial assembly receptor (MasR), for treating cancer cachexia. Plasmid overexpression of the MasR or pharmacologic angiotensin-(1-7)/MasR activation did not affect healthy muscle fiber size in vitro or in vivo but attenuated atrophy induced by coculture with cancer cells in vitro. In mice with cancer cachexia, the MasR agonist AVE 0991 slowed tumor development, reduced weight loss, improved locomotor activity, and attenuated muscle wasting, with the majority of these effects dependent on the orexigenic and not antitumor properties of AVE 0991. Proteomic profiling and IHC revealed that mechanisms underlying AVE 0991 effects on skeletal muscle involved miR-23a-regulated preservation of the fast, glycolytic fibers. MasR activation is a novel regulator of muscle phenotype, and AVE 0991 has orexigenic, anticachectic, and antitumorigenic effects, identifying it as a promising adjunct therapy for cancer and other serious muscle wasting conditions. SIGNIFICANCE: These findings demonstrate that MasR activation has multiple benefits of being orexigenic, anticachectic, and antitumorigenic, revealing it as a potential adjunct therapy for cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/4/706/F1.large.jpg.See related commentary by Rupert et al., p. 699.


Assuntos
Angiotensina I/metabolismo , Caquexia/prevenção & controle , Carcinoma Ductal Pancreático/prevenção & controle , Atrofia Muscular/prevenção & controle , Neoplasias Pancreáticas/prevenção & controle , Fragmentos de Peptídeos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Caquexia/etiologia , Caquexia/patologia , Carcinoma Ductal Pancreático/complicações , Carcinoma Ductal Pancreático/patologia , Estudos de Casos e Controles , Proliferação de Células , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Atrofia Muscular/etiologia , Atrofia Muscular/patologia , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/patologia , Prognóstico , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Receptores Acoplados a Proteínas G/genética , Células Tumorais Cultivadas
19.
Wetlands (Wilmington) ; 39(1): 127-137, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33424080

RESUMO

Wetlands can be significant sinks for Nr, via denitrification. There is a lack of understanding about factors controlling denitrification. Research suggests that hydrology, geomorphology, and nitrogen loading are dominant controls. We compared site-scale characteristics with denitrification enzyme activity (DEA) in wetlands along gradients of drainage basin land use to explore the relative importance of landscape and site-scale factors for determining denitrification potential. DEA rates ranged between 0.01-1.69 (µg N gdw-1 hr-1), with most sites falling at the lower end. Sites with higher DEA rates had higher percentages of soil carbon and nitrogen, concentrations of soil extractable NO3 and percent loss on ignition. Sites with upstream agricultural activity had higher DEA rates than more natural sites, but there existed a wide range of DEA rates along both agricultural and urban land gradients. When multiple site and landscape-scale explanatory factors were compared to DEA rates, two site and one landscape scale characteristic (Soil NO3, Soil Percent N, and Percent Agriculture) had significant (p<0.001, cum. r2 = 0.77) correlations with DEA rates. Our results suggest that DEA is controlled mainly by local-scale site characteristics with more work needed to determine the interdependencies and relative importance among these and potentially related landscape-scale factors.

20.
Aust J Prim Health ; 24(6): 455-462, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30452883

RESUMO

Clozapine is a high-risk medication with restrictions that may increase consumer treatment burden. Shared care may improve access, reduce burden and promote primary care management. However, knowledge about the consumer experience of clozapine treatment within a shared-care setting has not been previously reported to the authors' knowledge. The aim of this study was to explore the consumer experience within the shared-care setting. This mixed-methods study examined consumers' experiences with a clozapine shared-care program in an urban setting in Queensland, Australia. Eligible consumers (n=35) participated in a semi-structured interview, including a survey. Analysis was descriptive and thematic. Ten (28.6%) consumers participated. Survey results found a strong belief in the necessity for clozapine, with a low level of reported treatment burden and minimal adverse effects. Four themes were identified from the interviews: (i) understanding of illness and recovery; (ii) positive outcomes of treatment; (iii) acceptance of treatment burden; and (iv) communication pathways. Participants reported positive experiences in the clozapine shared-care program, citing clozapine's efficacy and the GP relationship as key benefits, however communication between clinicians and consumers must be enhanced to reduce risk of suboptimal treatment and adverse drug events.


Assuntos
Antipsicóticos/uso terapêutico , Clozapina/uso terapêutico , Conhecimentos, Atitudes e Prática em Saúde , Equipe de Assistência ao Paciente , Esquizofrenia/tratamento farmacológico , Adolescente , Adulto , Idoso , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Queensland , Resultado do Tratamento , População Urbana , Adulto Jovem
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