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1.
Mol Cell ; 82(15): 2858-2870.e8, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35732190

RESUMO

The tolerance of amino acid starvation is fundamental to robust cellular fitness. Asparagine depletion is lethal to some cancer cells, a vulnerability that can be exploited clinically. We report that resistance to asparagine starvation is uniquely dependent on an N-terminal low-complexity domain of GSK3α, which its paralog GSK3ß lacks. In response to depletion of specific amino acids, including asparagine, leucine, and valine, this domain mediates supramolecular assembly of GSK3α with ubiquitin-proteasome system components in spatially sequestered cytoplasmic bodies. This effect is independent of mTORC1 or GCN2. In normal cells, GSK3α promotes survival during essential amino acid starvation. In human leukemia, GSK3α body formation predicts asparaginase resistance, and sensitivity to asparaginase combined with a GSK3α inhibitor. We propose that GSK3α body formation provides a cellular mechanism to maximize the catalytic efficiency of proteasomal protein degradation in response to amino acid starvation, an adaptive response co-opted by cancer cells for asparaginase resistance.


Assuntos
Asparaginase , Leucemia , Aminoácidos/metabolismo , Asparaginase/genética , Asparaginase/metabolismo , Asparaginase/farmacologia , Asparagina , Humanos , Proteínas Serina-Treonina Quinases
2.
Br J Haematol ; 205(2): 624-633, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38934331

RESUMO

Studies on asparaginase enzyme activity (AEA) monitoring in Chinese patients receiving PEG-asparaginase remain limited. We monitored AEA in paediatric patients diagnosed with acute lymphoblastic leukaemia (ALL) and treated according to the Chinese Children's Cancer Group study protocols, CCCG-ALL-2015/CCCG-ALL-2020 protocols. We measured the AEA at days 7 ± 1 and 14 ± 1 and analysed their association with patient characteristics and PEG-asparaginase-related adverse effects (AEs). We measured 2147 samples from 329 patients. Mean AEA levels (interquartile range) were 931 iu/L (654-1174 iu/L) at day 7 ± 1 and 664 iu/L (463-860 iu/L) at day 14 ± 1. The AEA levels were higher in younger children and increased with the cumulative dose numbers. PEG-asparaginase inactivation rate was 19.1%, and the silent inactivation (SI) rate was 12.5%. Nine patients were identified with allergic-like reactions. Hypofibrinogenaemia, hypertriglyceridaemia, pancreatitis and thrombosis were associated with older age, whereas hypoglycaemia was associated with younger age. The risk of hypertriglyceridaemia and hypoglycaemia increased with cumulative dose numbers of PEG-asparaginase. Except for hypofibrinogenaemia, elevated AEA levels did not increase the risk of PEG-asparaginase-related AEs. Drug monitoring can be utilized as guidance for treatment decision-making. Individualizing asparaginase doses do not reduce toxicities. The treatment target of PEG-asparaginase remains to achieve sustained and adequate activity.


Assuntos
Asparaginase , Polietilenoglicóis , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Asparaginase/administração & dosagem , Asparaginase/efeitos adversos , China , População do Leste Asiático , Pancreatite/induzido quimicamente , Polietilenoglicóis/efeitos adversos , Polietilenoglicóis/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico
3.
Br J Haematol ; 204(6): 2324-2331, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38494194

RESUMO

Physiologically based pharmacokinetic (PBPK) modelling is an alternative modelling technique that is increasingly used in pharmacokinetics. Due to its nature, it can be complementarily employed to population pharmacokinetics, especially when it comes to small population size. Here, we report the proof of concept of its application to accurately describe the pharmacokinetics of a recombinant L-asparaginase in paediatric patients with acute lymphoblastic leukaemia. Data from two randomized, double-blind, phase II/III clinical studies (MC-ASP.4/ALL; MC-ASP.5/ALL) were included to setup and evaluate the final model, respectively. Final population values for basic pharmacokinetic parameters were calculated (clearance: 0.0569 L/h/19.5 kg, volume of distribution: 1.251 L, half-life: 18.5 h, trough concentration: 140.9 IU/L). Pharmacokinetic parameter prediction as well as predictive performance of the model proofed to be comparable to a separately developed population pharmacokinetic model with 13% deviation in predicted median L-asparaginase trough levels. To the best of our knowledge, this is the first whole-body PBPK model of a non-antibody therapeutic protein.


Assuntos
Asparaginase , Modelos Biológicos , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Asparaginase/farmacocinética , Asparaginase/uso terapêutico , Asparaginase/administração & dosagem , Criança , Pré-Escolar , Feminino , Masculino , Adolescente , Estudo de Prova de Conceito , Método Duplo-Cego , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Antineoplásicos/administração & dosagem , Lactente
4.
Br J Haematol ; 205(1): 175-188, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38736325

RESUMO

B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) blasts strictly depend on the transport of extra-cellular asparagine (Asn), yielding a rationale for L-asparaginase (ASNase) therapy. However, the carriers used by ALL blasts for Asn transport have not been identified yet. Exploiting RS4;11 cells as BCP-ALL model, we have found that cell Asn is lowered by either silencing or inhibition of the transporters ASCT2 or SNAT5. The inhibitors V-9302 (for ASCT2) and GluγHA (for SNAT5) markedly lower cell proliferation and, when used together, suppress mTOR activity, induce autophagy and cause a severe nutritional stress, leading to a proliferative arrest and a massive cell death in both the ASNase-sensitive RS4;11 cells and the relatively ASNase-insensitive NALM-6 cells. The cytotoxic effect is not prevented by coculturing leukaemic cells with primary mesenchymal stromal cells. Leukaemic blasts of paediatric ALL patients express ASCT2 and SNAT5 at diagnosis and undergo marked cytotoxicity when exposed to the inhibitors. ASCT2 expression is positively correlated with the minimal residual disease at the end of the induction therapy. In conclusion, ASCT2 and SNAT5 are the carriers exploited by ALL cells to transport Asn, and ASCT2 expression is associated with a lower therapeutic response. ASCT2 may thus represent a novel therapeutic target in BCP-ALL.


Assuntos
Sistema ASC de Transporte de Aminoácidos , Asparagina , Sobrevivência Celular , Antígenos de Histocompatibilidade Menor , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Humanos , Sistema ASC de Transporte de Aminoácidos/metabolismo , Sistema ASC de Transporte de Aminoácidos/genética , Asparagina/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Antígenos de Histocompatibilidade Menor/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Sobrevivência Celular/efeitos dos fármacos , Sistema A de Transporte de Aminoácidos/metabolismo , Sistema A de Transporte de Aminoácidos/genética , Linhagem Celular Tumoral , Asparaginase/farmacologia , Asparaginase/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Criança
5.
Toxicol Appl Pharmacol ; 485: 116920, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38582373

RESUMO

Asparaginase-associated pancreatitis (AAP) is a severe and potentially life-threatening drug-induced pancreas targeted toxicity in the combined chemotherapy of acute lymphoblastic leukemia among children and adolescents. The toxicological mechanism of AAP is not yet clear, and there are no effective preventive and treatment measures available clinically. Fibroblast growth factor 21 (FGF21) is a secretory hormone that regulates lipid, glucose, and energy metabolism balance. Acinar tissue is the main source of pancreatic FGF21 protein and plays an important role in maintaining pancreatic metabolic balance. In this study, we found that the decrease of FGF21 in pancreas is closely related to AAP. Pegaspargase (1 IU/g) induces widespread edema and inflammatory infiltration in the pancreas of rats/mice. The specific expression of FGF21 in the acinar tissue of AAP rats was significantly downregulated. Asparaginase caused dysregulation of the ATF4/ATF3/FGF21 axis in acinar tissue or cells, and thus mediated the decrease of FGF21. It greatly activated ATF3 in the acinar, which competed with ATF4 for the Fgf21 promoter, thereby inhibiting the expression of FGF21. Pharmacological replacement of FGF21 (1 mg/kg) or PERK inhibitors (GSK2656157, 25 mg/kg) can significantly mitigate the pancreatic tissue damage and reduce markers of inflammation associated with AAP, representing potential strategies for the prevention and treatment of AAP.


Assuntos
Asparaginase , Fatores de Crescimento de Fibroblastos , Pâncreas , Pancreatite , eIF-2 Quinase , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Asparaginase/toxicidade , Pancreatite/induzido quimicamente , Pancreatite/metabolismo , Pancreatite/patologia , Masculino , Ratos , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Pâncreas/metabolismo , Camundongos , Ratos Sprague-Dawley , Polietilenoglicóis/toxicidade , Antineoplásicos/toxicidade , Fator 4 Ativador da Transcrição/metabolismo , Fator 4 Ativador da Transcrição/genética , Camundongos Endogâmicos C57BL
6.
Biotechnol Bioeng ; 121(2): 535-550, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37927002

RESUMO

A new platform has been developed to facilitate the production of biologically active proteins and peptides in Escherichia coli. The platform includes an N-terminal self-associating L6 KD peptide fused to the SUMO protein (small ubiquitin-like protein modifier) from the yeast Saccharomyces cerevisiae, which is known for its chaperone activity. The target proteins are fused at the C termini of the L6 KD-SUMO fusions, and the resulting three-component fusion proteins are synthesized and self-assembled in E. coli into so-called active inclusion bodies (AIBs). In vivo, the L6 KD-SUMO platform facilitates the correct folding of the target proteins and directs them into AIBs, greatly simplifying their purification. In vitro, the platform facilitates the effective separation of AIBs by centrifugation and subsequent target protein release using SUMO-specific protease. The properties of the AIBs were determined using five proteins with different sizes, folding efficiencies, quaternary structure, and disulfide modifications. Electron microscopy shows that AIBs are synthesized in the form of complex fibrillar structures resembling "loofah sponges" with unusually thick filaments. The obtained results indicate that the new platform has promising features and could be developed to facilitate the synthesis and purification of target proteins and protein complexes without the use of renaturation.


Assuntos
Escherichia coli , Peptídeos , Escherichia coli/genética , Escherichia coli/metabolismo , Peptídeos/metabolismo , Dobramento de Proteína , Endopeptidases/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Corpos de Inclusão/genética , Corpos de Inclusão/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
7.
Cell Commun Signal ; 22(1): 163, 2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448969

RESUMO

Asparagine, an important amino acid in mammals, is produced in several organs and is widely used for the production of other nutrients such as glucose, proteins, lipids, and nucleotides. Asparagine has also been reported to play a vital role in the development of cancer cells. Although several types of cancer cells can synthesise asparagine alone, their synthesis levels are insufficient to meet their requirements. These cells must rely on the supply of exogenous asparagine, which is why asparagine is considered a semi-essential amino acid. Therefore, nutritional inhibition by targeting asparagine is often considered as an anti-cancer strategy and has shown success in the treatment of leukaemia. However, asparagine limitation alone does not achieve an ideal therapeutic effect because of stress responses that upregulate asparagine synthase (ASNS) to meet the requirements for asparagine in cancer cells. Various cancer cells initiate different reprogramming processes in response to the deficiency of asparagine. Therefore, it is necessary to comprehensively understand the asparagine metabolism in cancers. This review primarily discusses the physiological role of asparagine and the current progress in the field of cancer research.


Assuntos
Leucemia , Neoplasias , Animais , Asparagina , Aminoácidos , Glucose , Mamíferos
8.
Arch Microbiol ; 206(6): 266, 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38761213

RESUMO

We succeeded in homogeneously expressing and purifying L-asparaginase from Latilactobacillus sakei LK-145 (Ls-Asn1) and its mutated enzymes C196S, C264S, C290S, C196S/C264S, C196S/C290S, C264S/C290S, and C196S/C264S/C290S-Ls-Asn1. Enzymological studies using purified enzymes revealed that all cysteine residues of Ls-Asn1 were found to affect the catalytic activity of Ls-Asn1 to varying degrees. The mutation of Cys196 did not affect the specific activity, but the mutation of Cys264, even a single mutation, significantly decreased the specific activity. Furthermore, C264S/C290S- and C196S/C264S/C290S-Ls-Asn1 almost completely lost their activity, suggesting that C290 cooperates with C264 to influence the catalytic activity of Ls-Asn1. The detailed enzymatic properties of three single-mutated enzymes (C196S, C264S, and C290S-Ls-Asn1) were investigated for comparison with Ls-Asn1. We found that only C196S-Ls-Asn1 has almost the same enzymatic properties as that of Ls-Asn1 except for its increased stability for thermal, pH, and the metals NaCl, KCl, CaCl2, and FeCl2. We measured the growth inhibitory effect of Ls-Asn1 and C196S-Ls-Asn1 on Jurkat cells, a human T-cell acute lymphoblastic leukemia cell line, using L-asparaginase from Escherichia coli K-12 as a reference. Only C196S-Ls-Asn1 effectively and selectively inhibited the growth of Jurkat T-cell leukemia, which suggested that it exhibited antileukemic activity. Furthermore, based on alignment, phylogenetic tree analysis, and structural modeling, we also proposed that Ls-Asn1 is a so-called "Type IIb" novel type of asparaginase that is distinct from previously reported type I or type II asparaginases. Based on the above results, Ls-Asn1 is expected to be useful as a new leukemia therapeutic agent.


Assuntos
Asparaginase , Asparaginase/genética , Asparaginase/metabolismo , Asparaginase/química , Asparaginase/isolamento & purificação , Asparaginase/farmacologia , Humanos , Bacillaceae/enzimologia , Bacillaceae/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Concentração de Íons de Hidrogênio , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/metabolismo , Células Jurkat , Mutação , Sequência de Aminoácidos , Cinética
9.
Pharmacol Res ; 206: 107292, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39002867

RESUMO

Nutrient bioavailability in the tumor microenvironment plays a pivotal role in tumor proliferation and metastasis. Among these nutrients, glutamine is a key substance that promotes tumor growth and proliferation, and its downstream metabolite asparagine is also crucial in tumors. Studies have shown that when glutamine is exhausted, tumor cells can rely on asparagine to sustain their growth. Given the reliance of tumor cell proliferation on asparagine, restricting its bioavailability has emerged as promising strategy in cancer treatment. For instance, the use of asparaginase, an enzyme that depletes asparagine, has been one of the key chemotherapies for acute lymphoblastic leukemia (ALL). However, tumor cells can adapt to asparagine restriction, leading to reduced chemotherapy efficacy, and the mechanisms by which different genetically altered tumors are sensitized or adapted to asparagine restriction vary. We review the sources of asparagine and explore how limiting its bioavailability impacts the progression of specific genetically altered tumors. It is hoped that by targeting the signaling pathways involved in tumor adaptation to asparagine restriction and certain factors within these pathways, the issue of drug resistance can be addressed. Importantly, these strategies offer precise therapeutic approaches for genetically altered cancers.


Assuntos
Asparagina , Neoplasias , Humanos , Asparagina/metabolismo , Animais , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Antineoplásicos/uso terapêutico , Antineoplásicos/farmacologia , Microambiente Tumoral/efeitos dos fármacos , Terapia de Alvo Molecular
10.
Int Microbiol ; 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38519776

RESUMO

The L-asparaginase (ASPN) enzyme has received recognition in various applications including acrylamide degradation in the food industry. The synthesis and application of thermostable ASPN enzymes is required for its use in the food sector, where thermostable enzymes can withstand high temperatures. To achieve this goal, the bacterium Bacillus subtilis was isolated from the hot springs of Tapovan for screening the production of thermostable ASPN enzyme. Thus, ASPN with a maximal specific enzymatic activity of 0.896 U/mg and a molecular weight of 66 kDa was produced from the isolated bacteria. The kinetic study of the enzyme yielded a Km value of 1.579 mM and a Vmax of 5.009 µM/min with thermostability up to 100 min at 75 °C. This may have had a positive indication for employing the enzyme to stop polyacrylamide from being produced. The current study has also been extended to investigate the interaction of native and mutated ASPN enzymes with acrylamide. This concluded that the M10 (with 10 mutations) has the highest protein and thermal stability compared to the wild-type ASPN protein sequence. Therefore, in comparison to a normal ASPN and all other mutant ASPNs, M10 is the most favorable mutation. This research has also demonstrated the usage of ASPN in food industrial applications.

11.
Int Microbiol ; 27(5): 1405-1416, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38277111

RESUMO

The influence of light regulation on fungal growth and enzyme production was tested on endophytic isolates of Fusarium proliferatum (CCH), Colletotrichum boninense (PL1, PL9, OL2), Colletotrichum gloeosporiodes (OL3) and Colletotrichum siamense (PL3). The isolates were treated with blue, red, green, and yellow light, while white fluorescent light (12 h light/12 h dark photoperiod) and 24 h dark conditions were applied as control. Results revealed that coloured light treatments induced formation of circadian rings, while exposure to white light and dark conditions showed less pronounced circadian rings. Growth and sporulation of endophytes were not significantly influenced by light. By contrast, enzyme production was affected by coloured light treatments, notably with red (amylase), blue (cellulase) and yellow (cellulase, xylanase, L-asparaginase) light, resulting in lower enzyme levels for certain isolates. Under control conditions, enzyme production was relatively higher for amylase, cellulase, xylanase (for cultures incubated in the dark), and for L-asparaginase (for cultures incubated in white fluorescent light). Among the endophytic isolates, F. proliferatum (CCH) showed better response to coloured light treatment as higher sporulation and enzyme production was detected, although growth was significantly suppressed. On the contrary, C. gloeosporiodes (OL3) showed better growth but significantly lower enzyme production and sporulation when treated with the various coloured light. This study revealed that coloured light may have the potential to manipulate growth, sporulation and enzyme production in certain fungal species as strategies for fungal control or for harnessing of valuable enzymes.


Assuntos
Amilases , Colletotrichum , Endófitos , Fusarium , Luz , Endófitos/enzimologia , Endófitos/metabolismo , Endófitos/efeitos da radiação , Fusarium/crescimento & desenvolvimento , Fusarium/efeitos da radiação , Amilases/metabolismo , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/efeitos da radiação , Cor , Celulase/metabolismo , Celulase/biossíntese , Asparaginase/metabolismo , Proteínas Fúngicas/metabolismo
12.
Extremophiles ; 28(3): 44, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39313567

RESUMO

L-asparaginase (ASNase, E.C. 3.5.1.1) catalyzes the deamination of L-asparagine to L-aspartic acid and ammonia and is widely used in medicine to treat acute lymphocytic leukemia. It also has significant applications in the food industry by inhibiting acrylamide formation. In this study, we characterized a thermostable ASNase from the hyper thermophilic strain, Pyrococcus yayanosii CH1. The recombinant enzyme (PyASNase) exhibited maximal activity at pH 8.0 and 85 °C. Moreover, PyASNase demonstrated promising thermostability across temperatures ranging from 70 to 95 °C. The kinetic parameters of PyASNase for L-asparagine were a Km of 6.3 mM, a kcat of 1989s-1, and a kcat/Km of 315.7 mM-1 s-1. Treating potato samples with 10 U/mL of PyASNase at 85 °C for merely 10 min reduced the acrylamide content in the final product by 82.5%, demonstrating a high efficiency and significant advantage of PyASNase in acrylamide inhibition.


Assuntos
Acrilamida , Asparaginase , Estabilidade Enzimática , Pyrococcus , Asparaginase/química , Asparaginase/metabolismo , Asparaginase/genética , Acrilamida/química , Acrilamida/metabolismo , Pyrococcus/enzimologia , Proteínas Arqueais/metabolismo , Proteínas Arqueais/química , Proteínas Arqueais/genética , Temperatura Alta
13.
Pediatr Blood Cancer ; 71(4): e30891, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38311802

RESUMO

BACKGROUND: Pegaspargase is a therapeutic enzyme that is utilized in treatment regimens targeting pediatric acute lymphoblastic leukemia. However, many patients experience hypersensitivity reactions, requiring discontinuation of the therapy. Historically, this necessitated switching to an alternative form of the drug, most commonly asparaginase Erwinia chrysanthemi; however, in recent years this was difficult due to drug shortages and eventually commercial discontinuation. We report here our experience performing pegaspargase desensitizations in patients with prior hypersensitivity reactions. PROCEDURE: Patients with a clinical hypersensitivity reaction to pegaspargase were identified. When due for their next dose, patients were admitted to the pediatric intensive care unit, bone marrow transplant unit, or oncology unit, and underwent desensitization utilizing a rigorous premedication and multistep dilution-based protocol. Serum asparaginase activity levels were drawn after desensitization to assess for therapeutic levels of enzyme activity. RESULTS: We identified 11 patients who underwent a total of 33 desensitizations to pegaspargase and calaspargase pegol-mknl. No patients experienced clinically significant hypersensitivity reactions necessitating stopping the infusion, nor administration of rescue medications. All serum asparaginase activity levels collected demonstrated enzyme activity levels above predefined therapeutic thresholds. Cost analysis revealed substantial savings when patients received asparaginase desensitization over the now commercially available asparaginase E. chrysanthemi (recombinant) rywn. CONCLUSIONS: Performing desensitization to pegaspargase in the pediatric acute lymphoblastic leukemia population is feasible, safe, and effective. It is financially advantageous over available alternative approaches, and requires fewer injections and presentations to care.


Assuntos
Antineoplásicos , Hipersensibilidade a Drogas , Erwinia , Hipersensibilidade , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Asparaginase/efeitos adversos , Antineoplásicos/uso terapêutico , Hipersensibilidade a Drogas/etiologia , Hipersensibilidade a Drogas/tratamento farmacológico , Polietilenoglicóis/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico
14.
Thromb J ; 22(1): 30, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38539225

RESUMO

BACKGROUND: Thromboembolic complications are well known in the treatment of childhood acute lymphoblastic leukemia. Over the years it has not been possible to reach a consensus on a possible prophylaxis of thromboembolic events during intensive therapy. Only the administration of enoxaparin was able to achieve evidence in the literature to date. METHODS: In this retrospective study, 173 childhood leukemia patients were treated over 20 years with a thromboembolic prophylaxis including enoxaparin and AT III during induction therapy with L-asparaginase and cortisone. RESULTS: We here report the effectiveness of administration of enoxaparin and AT III in childhood leukemia, showing a strikingly low prevalence of deep vein thrombosis (2.9%). Especially in adolescent patients, a particularly great need for AT III was demonstrated. CONCLUSIONS: We recommend thromboembolic prophylaxis with enoxaparin and AT III substitution during induction/reinduction therapy with L-asparaginase and glucocorticosteroids, especially from adolescence onwards.

15.
Future Oncol ; 20(28): 2071-2081, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39041580

RESUMO

Aim: This multicenter retrospective study aimed to develop a novel prognostic system for extranodal natural killer/T-cell lymphoma (ENKTL) patients in the era of pegaspargase/L-asparaginase.Materials & methods: A total of 844 newly diagnosed ENKTL patients were included.Results: Multivariable analysis confirmed that Eastern Cooperative Oncology Group performance status, lactate dehydrogenase, Chinese Southwest Oncology Group and Asia Lymphoma Study Group ENKTL (CA) system, and albumin were independent prognostic factors. By rounding up the hazard ratios from four significant variables, a maximum of 7 points were assigned. The model of Huaihai Lymphoma Working Group-Natural killer/T-cell Lymphoma prognostic index (NPI) was identified with four risk groups and the 5-year overall survival was 88.2, 66.7, 54.3 and 30.5%, respectively.Conclusion: Huaihai Lymphoma Working Group-NPI provides a feasible stratification system for patients with ENKTL in the era of pegaspargase/L-asparaginase.


[Box: see text].


Assuntos
Asparaginase , Linfoma Extranodal de Células T-NK , Polietilenoglicóis , Humanos , Linfoma Extranodal de Células T-NK/tratamento farmacológico , Linfoma Extranodal de Células T-NK/mortalidade , Linfoma Extranodal de Células T-NK/diagnóstico , Linfoma Extranodal de Células T-NK/patologia , Asparaginase/uso terapêutico , Feminino , Polietilenoglicóis/uso terapêutico , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto , Estudos Retrospectivos , Adolescente , Idoso , Adulto Jovem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança
16.
Future Oncol ; : 1-11, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39378065

RESUMO

Asparagine synthetase (ASNS) catalyzes the biosynthesis of asparagine from aspartate and glutamine. Cells lacking ASNS, however, are auxotrophic for asparagine. Use of L-asparaginase to promote asparagine starvation in solid tumors with low ASNS levels, such as pancreatic ductal adenocarcinoma (PDAC), is a rationale treatment strategy. However, tumor cell resistance to L-asparaginase has limited its clinical utility. Our preclinical studies show that RAS/MAPK signaling circumvents L-asparaginase-induced tumor killing, but L-asparaginase and MEK inhibition potentiated tumor killing; suggesting that this combination may provide meaningful clinical benefit to patients with PDAC. This Phase I trial (NCT05034627) will evaluate the safety and tolerability of the MEK inhibitor, cobimetinib, in combination with pegylated L-asparaginase, L calaspargase pegol-mknl, in patients with locally-advanced or metastatic PDAC.


[Box: see text].

17.
Exp Cell Res ; 426(2): 113568, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-36967104

RESUMO

l-Asparaginase is a cornerstone of acute lymphoblastic leukemia (ALL) therapy since lymphoblasts lack asparagine synthetase (ASNS) and rely on extracellular asparagine availability for survival. Resistance mechanisms are associated with increased ASNS expression in ALL. However, the association between ASNS and l-Asparaginase efficacy in solid tumors remains unclear, thus limiting clinical development. Interestingly, l-Asparaginase also has a glutaminase co-activity that is crucial in pancreatic cancer where KRAS mutations activate glutamine metabolism. By developing l-Asparaginase-resistant pancreatic cancer cells and using OMICS approaches, we identified glutamine synthetase (GS) as a marker of resistance to l-Asparaginase. GS is the only enzyme able to synthesize glutamine, and its expression also correlates with l-Asparaginase efficacy in 27 human cell lines from 11 cancer indications. Finally, we further demonstrated that GS inhibition prevents cancer cell adaptation to l-Asparaginase-induced glutamine starvation. These findings could pave the way to the development of promising drug combinations to overcome l-Asparaginase resistance.


Assuntos
Neoplasias Pancreáticas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Asparaginase/farmacologia , Glutamato-Amônia Ligase/genética , Glutaminase/genética , Glutamina/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Neoplasias Pancreáticas
18.
Environ Res ; 259: 119543, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38964574

RESUMO

This research was designed to isolate the predominant L-asparaginase-producing fungus from rhizosphere soil of tapioca field and assess the suitable growth conditions required to produce maximum L-asparaginase activity. The Aspergillus tubingensis was identified as a predominant L-asparaginase producing fungal isolate from 15 isolates, and it was characterized by 18S rRNA sequencing. The L-asparaginase-producing activity was confirmed by pink color zone formation around the colonies in modified Czapek Dox agar plate supplemented with 1% L-Asparagine. The optimal growth conditions required for the L-asparaginase production by A. tubingensis were optimized as pH 6.0, temperature 30 °C, glucose as carbon source, 1.5% of L-Asparagine, ammonium sulphate as nitrogen source, rice husk as natural L-Asparagine enriched source, and 8 days of the incubation period. The L-Asparaginase activity from A. tubingensis was excellent under these optimal growth conditions. It significantly used rice husk as an alternative to synthetic L-Asparagine. As a result, this may be considered a sustainable method of converting organic waste into valuable raw material for microbial enzyme production.


Assuntos
Asparaginase , Aspergillus , Microbiologia do Solo , Asparaginase/biossíntese , Asparaginase/metabolismo , Aspergillus/metabolismo , Aspergillus/crescimento & desenvolvimento , Aspergillus/enzimologia , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Temperatura
19.
J Sep Sci ; 47(14): e2400141, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39054594

RESUMO

Hydroxyapatite (HAp) is a calcium phosphate ceramic, widely used as a matrix for protein chromatography. The crystal structure of HAp is amenable to a wide range of substitutions, thus allowing for the alteration of its properties. In this study, nickel-ion substituted HAp (NiSHAp) was synthesized using a wet-precipitation method, followed by spray drying. This resulted in the structural incorporation of nickel ions within well-defined microspheres, which were suitable for chromatographic applications. The chromatographic experiments were conducted with NiSHAp and compared with spray-dried hydroxyapatite (SHAp) matrices. Protein purification experiments were conducted using refolded recombinant L-asparaginase (L-Asp), which was produced as inclusion bodies in Escherichia coli. The results showed that NiSHAp effectively adsorbed L-Asp, which was selectively eluted using a phosphate buffer, surpassing the efficiency of imidazole-based elution. In contrast, SHAp showed weaker binding and lower selectivity. The significance of this study lies in developing a scalable NiSHAp matrix for protein purification, especially for large-scale applications. The NiSHAp matrix offers a cost-effective alternative to commercial immobilized metal affinity chromatography (IMAC) adsorbents, especially for purifying His-tagged proteins. This innovative approach exhibits the advantages of mixed-mode chromatography by combining the properties of hydroxyapatite and IMAC in a single matrix, with the potential of improved industrial-scale protein purification.


Assuntos
Cromatografia de Afinidade , Durapatita , Níquel , Proteínas Recombinantes , Durapatita/química , Cromatografia de Afinidade/métodos , Níquel/química , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Escherichia coli/química , Adsorção
20.
Lett Appl Microbiol ; 77(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37563083

RESUMO

This study reports the antioxidant potential and L-asparaginase production of culturable fungal endophytes from Dendrobium orchids in Malaysia. Twenty-nine isolates were screened using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay to determine their free radical scavenging activities and antioxidant capacity (IC50 and AEAC). L-asparaginase production of fungal endophytes was detected by the qualitative plate assay, and the enzyme activities estimated via the Nesslerization method. All 29 endophytic isolates exhibited various degrees of radical scavenging activities (35.37%-77.23%), with Fusarium fujikuroi (D1) identified as having the highest antioxidant capacity (IC50 6.097 mg/mL) and the highest AEAC value (11.55  mg/g). For L-asparaginase production, the majority of the isolates (89.66%) showed positive results, especially among the culturable species of Fusarium, Trichoderma, and Daldinia. Most Fusarium spp. were able to produce L-asparaginase (80.77%), but the highest L-asparaginase activity was detected in Daldinia eschscholtzii (D14) with 2.128 units/mL. Results from this study highlighted the potential of endophytic fungi from medicinal orchids (Dendrobium sp.) as natural sources of bioactive compounds to be developed into novel antioxidants and anticancer drugs.


Assuntos
Antineoplásicos , Dendrobium , Fungos , Asparaginase , Antioxidantes/farmacologia , Endófitos
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